Company lists · Data refreshed September 2026
Top 21 Spam filtering companies based in the United States
RevenueBase identified 49 company matches for spam filtering companies associated with the United States as of September 2026 and tracks 1,227 professional contacts across them, including 310 with verified work emails. San Francisco is the largest hub.
This list covers company matches for spam filtering companies associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 22, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 21 largest spam filtering companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 236 contacts → | ||||
Exact match “Sublime is the new standard for email security.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 2 | 200 contacts → | ||||
Exact match “Zix, an OpenText company, is a leader in email security and helps organizations overcome their greatest digital transformation challenges by providing a secure, modern workplace.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 3 | 129 contacts → | ||||
Exact match “EasyDMARC is your one-stop platform that secures your email domain infrastructure and boosts email deliverability for your peace of mind.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 4 | 53 contacts → | ||||
Exact match “Cloudmark was acquired by Proofpoint.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 5 | 43 contacts → | ||||
Exact match “PowerDMARC empowers organizations to combat Business Email Compromise (BEC), email spoofing, and phishing with ease.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 6 | 39 contacts → | ||||
Exact match “Cyren, now part of Data443, protects hundreds of millions of users around the world from sophisticated and emerging email, malware, and web attacks every day.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 7 | 26 contacts → | ||||
Exact match “Abnormal provides total protection against the widest range of email attacks including phishing, malware, ransomware, social engineering, executive impersonation, supply chain…” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 8 | 23 contacts → | ||||
Exact match “Cloudflare Area 1 is a cloud-native email security service that identifies and blocks attacks before they hit user inboxes, enabling more effective protection against spear…” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 9 | 20 contacts → | ||||
Exact match “CleanTalk is a SaaS spam protection service for Web sites.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 10 | 19 contacts → | ||||
Exact match “Founded in 2003, Sendio is a venture-backed, privately held company whose products protect the email environments of enterprises and institutions from attacks and abuse, and…” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 11 | 16 contacts → | ||||
Exact match “MailGate SC is a comprehensive email security solution that protects your organization from a wide range of advanced threats.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 12 | 15 contacts → | ||||
Exact match “Spambrella is a Worldwide email content control security ‘software as a service’ (SaaS) provider.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 13 | 15 contacts → | ||||
Exact match “EdgeWave is hyper-focused on delivering the World’s Safest Inboxes™ by eliminating email-borne security risks for organizations in the face of targeted, socially engineered…” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 14 | 14 contacts → | ||||
Exact match “Agari is the Trusted Email Identity Company™, protecting brands and people from devastating phishing and socially-engineered attacks.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 15 | 14 contacts → | ||||
Exact match “Maysoft has been stopping spam and viruses for over 10 years.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 16 | 12 contacts → | ||||
Exact match “Global companies use GreatHorn to reduce the inherent and pervasive risk associated with the everyday use of email.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 17 | 10 contacts → | ||||
Exact match “At Identillect Technologies, we create a user-friendly secure email solution to protect critical information, with an emphasis on simplicity.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 18 | 8 contacts → | ||||
Exact match “Down-to earth Cloud services.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 19 | 5 contacts → | ||||
Exact match “Mailshell is the leading provider of Internet filtering engines and SDK for OEMs, including email reputation, anti-spam, anti-phishing, URL categorization and DNS security.” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 20 | 4 contacts → | ||||
Exact match “MX Layer is a cyber-security company developing an easy-to-use Cloud Email Security Platform offering email protection and data retention services” Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
| 21 | 1 contacts → | ||||
Exact match Recorded description not available. Recorded in the RevenueBase company graph · Sep 22, 2026 · View company records in RevenueBase | |||||
RevenueBase SmartSearch
Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.
This list uses Exact for “spam filtering companies”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.
Showing 21 of 49 spam filtering companies based in the United States
See the full list, filter by size, metro and specialty, and access 310 tracked professional contacts with verified work emails. Direct dials are available where recorded.
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Spam filtering companies based in the United States at a glance
As of Sep 22, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 49 companies.
How this list was built
The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
- What qualifies
- Company records associated with the United States whose business descriptions match “spam filtering companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
- RevenueBase SmartSearch
- Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
- Public preview
- The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
- Match quality
- RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every displayed company carries at least one verified work email. RevenueBase tracks 310 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 22, 2026. Lists refresh periodically as the graph is re-checked.
- Record context
- Company records and descriptions can change. Check the company's website for its current services and locations.
Frequently asked
What is RevenueBase SmartSearch?
RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “spam filtering companies”; each Exact match badge shows search membership, not an individual similarity or quality score.
How many spam filtering companies are there based in the United States?
RevenueBase identified 49 company matches for spam filtering companies associated with the United States as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.
What is the largest company on this list?
Sublime Security tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.
Which city has the most spam filtering companies?
San Francisco leads with 6 company records, followed by Atlanta (2) and Chicago (2).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 310 professional contacts with verified work emails tracked across these 49 companies; direct dials are available where recorded.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 22, 2026.
Ready to reach these companies? Verified emails and direct dials for all 49 spam filtering companies based in the United States. Start with a free account, no credit card.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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Company intelligence · public preview
Top 21 spam filtering companies based in the United States
Find companies in any niche.
Describe the businesses you want in your own words. RevenueBase SmartSearch matches company descriptions by meaning.
RevenueBase records 49 matching company records for spam filtering companies based in the United States, with 1,227 tracked contacts and 310 verified work emails.
This public preview shows 21 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: September 22, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 21 spam filtering companies based in the United States
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 |  Sublime Securitysublime.securityHQ: Washington, DC, United StatesReported employees: 201-500 | Washington, DC, United States | 201-500 | Exact match | 236 contacts → |
“Sublime is the new standard for email security.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 |  ZIXzix.comHQ: Dallas, TX, United StatesReported employees: 501-1,000 | Dallas, TX, United States | 501-1,000 | Exact match | 200 contacts → |
“Zix, an OpenText company, is a leader in email security and helps organizations overcome their greatest digital transformation challenges by providing a secure, modern workplace.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 |  Easydmarceasydmarc.comHQ: Dover, DE, United StatesReported employees: 51-200 | Dover, DE, United States | 51-200 | Exact match | 129 contacts → |
“EasyDMARC is your one-stop platform that secures your email domain infrastructure and boosts email deliverability for your peace of mind.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 |  Cloudmarkcloudmark.comHQ: San Francisco, CA, United StatesReported employees: 51-200 | San Francisco, CA, United States | 51-200 | Exact match | 53 contacts → |
“Cloudmark was acquired by Proofpoint.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 |  Powerdmarcpowerdmarc.comHQ: Middletown, DE, United StatesReported employees: 51-200 | Middletown, DE, United States | 51-200 | Exact match | 43 contacts → |
“PowerDMARC empowers organizations to combat Business Email Compromise (BEC), email spoofing, and phishing with ease.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 |  Cyren By Data443data443.comHQ: Research Triangle Park, NC, United StatesReported employees: 201-500 | Research Triangle Park, NC, United States | 201-500 | Exact match | 39 contacts → |
“Cyren, now part of Data443, protects hundreds of millions of users around the world from sophisticated and emerging email, malware, and web attacks every day.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 | Abnormal Securityabnormalsecurity.com HQ: San Francisco, CA, United StatesReported employees: 501-1,000 | San Francisco, CA, United States | 501-1,000 | Exact match | 26 contacts → |
“Abnormal provides total protection against the widest range of email attacks including phishing, malware, ransomware, social engineering, executive impersonation, supply chain…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 |  Cloudflare Area 1 Securitycloudflare.comHQ: San Francisco, CA, United StatesReported employees: 51-200 | San Francisco, CA, United States | 51-200 | Exact match | 23 contacts → |
“Cloudflare Area 1 is a cloud-native email security service that identifies and blocks attacks before they hit user inboxes, enabling more effective protection against spear…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 |  Cleantalk INCcleantalk.orgHQ: Carson City, NV, United StatesReported employees: 1-10 | Carson City, NV, United States | 1-10 | Exact match | 20 contacts → |
“CleanTalk is a SaaS spam protection service for Web sites.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 |  Sendio Technologies, INCsendio.comHQ: Newport Beach, CA, United StatesReported employees: 11-50 | Newport Beach, CA, United States | 11-50 | Exact match | 19 contacts → |
“Founded in 2003, Sendio is a venture-backed, privately held company whose products protect the email environments of enterprises and institutions from attacks and abuse, and…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 |  Mailgatemailgatesc.comHQ: Greenwood, IN, United StatesReported employees: 11-50 | Greenwood, IN, United States | 11-50 | Exact match | 16 contacts → |
“MailGate SC is a comprehensive email security solution that protects your organization from a wide range of advanced threats.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 |  Spambrellaspambrella.comHQ: Dover, DE, United StatesReported employees: 51-200 | Dover, DE, United States | 51-200 | Exact match | 15 contacts → |
“Spambrella is a Worldwide email content control security ‘software as a service’ (SaaS) provider.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 |  Edgewaveedgewave.comHQ: La Jolla, CA, United StatesReported employees: 51-200 | La Jolla, CA, United States | 51-200 | Exact match | 15 contacts → |
“EdgeWave is hyper-focused on delivering the World’s Safest Inboxes™ by eliminating email-borne security risks for organizations in the face of targeted, socially engineered…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 | AGARIagari.com HQ: Foster City, CA, United StatesReported employees: 51-200 | Foster City, CA, United States | 51-200 | Exact match | 14 contacts → |
“Agari is the Trusted Email Identity Company™, protecting brands and people from devastating phishing and socially-engineered attacks.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 |  Maysoftmaysoft.comHQ: Santa Barbara, CA, United StatesReported employees: 11-50 | Santa Barbara, CA, United States | 11-50 | Exact match | 14 contacts → |
“Maysoft has been stopping spam and viruses for over 10 years.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 |  Greathorngreathorn.comHQ: Waltham, MA, United StatesReported employees: 11-50 | Waltham, MA, United States | 11-50 | Exact match | 12 contacts → |
“Global companies use GreatHorn to reduce the inherent and pervasive risk associated with the everyday use of email.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 |  Identillect Technologies INCidentillect.comHQ: Poway, CA, United StatesReported employees: 11-50 | Poway, CA, United States | 11-50 | Exact match | 10 contacts → |
“At Identillect Technologies, we create a user-friendly secure email solution to protect critical information, with an emphasis on simplicity.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 |  ISP Cloud Services INCispcloudservices.comHQ: Miami, FL, United StatesReported employees: 1-10 | Miami, FL, United States | 1-10 | Exact match | 8 contacts → |
“Down-to earth Cloud services.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 |  Mailshellmailshell.comHQ: San Francisco, CA, United StatesReported employees: 11-50 | San Francisco, CA, United States | 11-50 | Exact match | 5 contacts → |
“Mailshell is the leading provider of Internet filtering engines and SDK for OEMs, including email reputation, anti-spam, anti-phishing, URL categorization and DNS security.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 |  MX Layermxlayer.comHQ: Las Vegas, NV, United StatesReported employees: 11-50 | Las Vegas, NV, United States | 11-50 | Exact match | 4 contacts → |
“MX Layer is a cyber-security company developing an easy-to-use Cloud Email Security Platform offering email protection and data retention services” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 |  RAE Internet INCraeinternet.comHQ: Tarrytown, NY, United StatesReported employees: 11-50 | Tarrytown, NY, United States | 11-50 | Exact match | 1 contacts → |
No recorded description excerpt is available for this public record. | |||||
Showing 21 of 49 company matches
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Spam filtering companies: dataset insights
September 22, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
49 records in the displayed employee bands.
0 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 49 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: September 22, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Questions about this company list
What does Exact match mean for spam filtering companies?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many spam filtering companies did RevenueBase find based in the United States?
The saved snapshot records 49 matching company records, 1,227 tracked contacts and 310 verified emails. The public preview displays 21 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: September 22, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
Cite this list
RevenueBase Data Team. Top 21 spam filtering companies based in the United States. Snapshot: September 22, 2026. https://revenuebase.ai/companies/spam-filtering-companies/united-states.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- AI companies based in the United States
- Cybersecurity companies based in the United States
- Manufacturing companies based in the United States
- Media companies based in the United States
- Oil and gas companies based in the United States
- Real estate companies based in the United States
Company intelligence · public preview
Top 21 spam filtering companies based in the United States
RevenueBase records 49 matching company records for spam filtering companies based in the United States, with 1,227 tracked contacts and 310 verified work emails.
This public preview shows 21 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: September 22, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 21 spam filtering companies based in the United States
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 | Sublime Securitysublime.security HQ: Washington, DC, United StatesReported employees: 201-500 | Washington, DC, United States | 201-500 | Exact match | 236 contacts → |
“Sublime is the new standard for email security.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 | ZIXzix.com HQ: Dallas, TX, United StatesReported employees: 501-1,000 | Dallas, TX, United States | 501-1,000 | Exact match | 200 contacts → |
“Zix, an OpenText company, is a leader in email security and helps organizations overcome their greatest digital transformation challenges by providing a secure, modern workplace.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 | Easydmarceasydmarc.com HQ: Dover, DE, United StatesReported employees: 51-200 | Dover, DE, United States | 51-200 | Exact match | 129 contacts → |
“EasyDMARC is your one-stop platform that secures your email domain infrastructure and boosts email deliverability for your peace of mind.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 | Cloudmarkcloudmark.com HQ: San Francisco, CA, United StatesReported employees: 51-200 | San Francisco, CA, United States | 51-200 | Exact match | 53 contacts → |
“Cloudmark was acquired by Proofpoint.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 | Powerdmarcpowerdmarc.com HQ: Middletown, DE, United StatesReported employees: 51-200 | Middletown, DE, United States | 51-200 | Exact match | 43 contacts → |
“PowerDMARC empowers organizations to combat Business Email Compromise (BEC), email spoofing, and phishing with ease.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 | Cyren By Data443data443.com HQ: Research Triangle Park, NC, United StatesReported employees: 201-500 | Research Triangle Park, NC, United States | 201-500 | Exact match | 39 contacts → |
“Cyren, now part of Data443, protects hundreds of millions of users around the world from sophisticated and emerging email, malware, and web attacks every day.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 | Abnormal Securityabnormalsecurity.com HQ: San Francisco, CA, United StatesReported employees: 501-1,000 | San Francisco, CA, United States | 501-1,000 | Exact match | 26 contacts → |
“Abnormal provides total protection against the widest range of email attacks including phishing, malware, ransomware, social engineering, executive impersonation, supply chain…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 | Cloudflare Area 1 Securitycloudflare.com HQ: San Francisco, CA, United StatesReported employees: 51-200 | San Francisco, CA, United States | 51-200 | Exact match | 23 contacts → |
“Cloudflare Area 1 is a cloud-native email security service that identifies and blocks attacks before they hit user inboxes, enabling more effective protection against spear…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 | Cleantalk INCcleantalk.org HQ: Carson City, NV, United StatesReported employees: 1-10 | Carson City, NV, United States | 1-10 | Exact match | 20 contacts → |
“CleanTalk is a SaaS spam protection service for Web sites.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 | Sendio Technologies, INCsendio.com HQ: Newport Beach, CA, United StatesReported employees: 11-50 | Newport Beach, CA, United States | 11-50 | Exact match | 19 contacts → |
“Founded in 2003, Sendio is a venture-backed, privately held company whose products protect the email environments of enterprises and institutions from attacks and abuse, and…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 | Mailgatemailgatesc.com HQ: Greenwood, IN, United StatesReported employees: 11-50 | Greenwood, IN, United States | 11-50 | Exact match | 16 contacts → |
“MailGate SC is a comprehensive email security solution that protects your organization from a wide range of advanced threats.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 | Spambrellaspambrella.com HQ: Dover, DE, United StatesReported employees: 51-200 | Dover, DE, United States | 51-200 | Exact match | 15 contacts → |
“Spambrella is a Worldwide email content control security ‘software as a service’ (SaaS) provider.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 | Edgewaveedgewave.com HQ: La Jolla, CA, United StatesReported employees: 51-200 | La Jolla, CA, United States | 51-200 | Exact match | 15 contacts → |
“EdgeWave is hyper-focused on delivering the World’s Safest Inboxes™ by eliminating email-borne security risks for organizations in the face of targeted, socially engineered…” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 | AGARIagari.com HQ: Foster City, CA, United StatesReported employees: 51-200 | Foster City, CA, United States | 51-200 | Exact match | 14 contacts → |
“Agari is the Trusted Email Identity Company™, protecting brands and people from devastating phishing and socially-engineered attacks.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 | Maysoftmaysoft.com HQ: Santa Barbara, CA, United StatesReported employees: 11-50 | Santa Barbara, CA, United States | 11-50 | Exact match | 14 contacts → |
“Maysoft has been stopping spam and viruses for over 10 years.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 | Greathorngreathorn.com HQ: Waltham, MA, United StatesReported employees: 11-50 | Waltham, MA, United States | 11-50 | Exact match | 12 contacts → |
“Global companies use GreatHorn to reduce the inherent and pervasive risk associated with the everyday use of email.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 | Identillect Technologies INCidentillect.com HQ: Poway, CA, United StatesReported employees: 11-50 | Poway, CA, United States | 11-50 | Exact match | 10 contacts → |
“At Identillect Technologies, we create a user-friendly secure email solution to protect critical information, with an emphasis on simplicity.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 | ISP Cloud Services INCispcloudservices.com HQ: Miami, FL, United StatesReported employees: 1-10 | Miami, FL, United States | 1-10 | Exact match | 8 contacts → |
“Down-to earth Cloud services.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 | Mailshellmailshell.com HQ: San Francisco, CA, United StatesReported employees: 11-50 | San Francisco, CA, United States | 11-50 | Exact match | 5 contacts → |
“Mailshell is the leading provider of Internet filtering engines and SDK for OEMs, including email reputation, anti-spam, anti-phishing, URL categorization and DNS security.” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 | MX Layermxlayer.com HQ: Las Vegas, NV, United StatesReported employees: 11-50 | Las Vegas, NV, United States | 11-50 | Exact match | 4 contacts → |
“MX Layer is a cyber-security company developing an easy-to-use Cloud Email Security Platform offering email protection and data retention services” Recorded description excerpt · September 22, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 | RAE Internet INCraeinternet.com HQ: Tarrytown, NY, United StatesReported employees: 11-50 | Tarrytown, NY, United States | 11-50 | Exact match | 1 contacts → |
No recorded description excerpt is available for this public record. | |||||
Showing 21 of 49 company matches
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Spam filtering companies: dataset insights
September 22, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
49 records in the displayed employee bands.
0 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 49 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: September 22, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Questions about this company list
What does Exact match mean for spam filtering companies?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many spam filtering companies did RevenueBase find based in the United States?
The saved snapshot records 49 matching company records, 1,227 tracked contacts and 310 verified emails. The public preview displays 21 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: September 22, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
Cite this list
RevenueBase Data Team. Top 21 spam filtering companies based in the United States. Snapshot: September 22, 2026. https://revenuebase.ai/companies/spam-filtering-companies/united-states.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
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