Companies Using MailChannels

I knew MailChannels from SPF records, as the relay web hosts use to get their customers' mail delivered. This page counts something else. Our October 2026 crawl finds 67,894 domains whose MX record points at mailchannels.net, which means MailChannels filters their incoming mail. 35,668 of those domains match a company, and most of the owners have no idea MailChannels is involved, because their web host set it up.

Two products, one name

MailChannels sells Outbound Filtering to hosts, an SMTP relay that domains authorise with include:relay.mailchannels.net in SPF, plus an Email API and Inbound Filtering. Its inbound page pitches hosts on one thing: one MX record protects every domain across the fleet. Only that product shows in an MX record, so only that product is on this page. Relay users need a different signal.

Sales signal: if you sell deliverability or relay services, this is the wrong list. These are inbound-filtered mailboxes on shared hosts.

DreamHost's switch

The concentration is the finding. DreamHost's help centre says a domain's MX records read mx1 and mx2.mailchannels.net when spam filtering is enabled, and mx1 and mx2.dreamhost.com when it isn't. DreamHost shows on 80.2% of our MailChannels domains. In a live check of 1,000 random domains on 15 October 2026, 649 served their website from DreamHost's network and 586 used DreamHost's nameservers. The other hosts in that sample were small: InMotion Hosting (14), Web4U in the Czech Republic (12), Miss Hosting in Sweden (10). Every vendor MX we saw used the same two hostnames, mx1 and mx2.mailchannels.net, so no reseller name ever appears in the record.

Sales signal: for most of this list, the decision about mail filtering sits with DreamHost. One partnership there moves more domains than thousands of individual pitches.

A step, then a flat line

The chart reads 59,365 domains in June 2026, 65,697 in July and 67,894 in October. The July step is mostly ours: the domains we crawl turn over every month, dead sites out and new ones in, and our detection widens over time. From July the line is nearly flat, which is what you'd expect from a filter that changes only when a host changes its setup. 972 of the 1,000 domains we sampled still sent mail to MailChannels.

"MailChannels' inbound count is a measure of how many DreamHost customers leave spam filtering switched on. The owners chose a host, not a filter." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: don't read growth into this line. The addressable base is stable at about 68,000 domains and moves with DreamHost.

Who the owners are

Tiny businesses. 78.66% of matched companies with a known size have 1 to 10 staff and only 104 have more than 1,000. They are older than you might expect, though: 42.57% were founded in the 2010s and 22.51% in the 2000s. The United States holds 16,539 matched companies, 46.37% of the total, and Brazil is a clear second at 2,475, with Latin America at 4,442 once Mexico, Argentina, Chile and Colombia are added. No industry passes 3.57%: advertising, retail, IT services, consulting and construction lead a list that reads like a host's billing system.

Sales signal: the Brazilian and Mexican slice is unusual for an email-security list and worth a Portuguese and Spanish campaign of its own.

Leaving MailChannels means leaving the host

One switching flow passes our tests: 28 domains moved from MailChannels to Jellyfish since March 2026, and none came back. Jellyfish is Namecheap's built-in filter, and 19 of the 28 now use Namecheap's hosting nameservers. Those owners changed host and got a new filter with it. The wider exit numbers say the same. 2,654 domains have dropped MailChannels since 16 March 2026; of the 2,635 that left on every hostname, 201 now point their MX at Microsoft 365 and 92 at Google Workspace.

"Almost nobody in our data left MailChannels for another gateway. They moved hosts, or they moved their mailboxes to Microsoft or Google." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: the 293 domains now on Microsoft 365 or Google Workspace show the upgrade that does happen: a small firm outgrowing host-provided mail. Hosted mailbox and migration offers fit that moment.

The stack around it

WordPress runs on 60.21% of the domains in our stack sample, Divi on 5.47% and BoldGrid on 3.89%, with Google Analytics on 38.38%. The page titles show how many sites are idle: 635 still carry a version of "Just another WordPress site" and 341 show a WordPress database error. Their mail filtering keeps working regardless, because the MX record doesn't care whether the website does. Microsoft 365 (0.11%) and Google Workspace (0.14%) barely show, since both of our signals read the same MX record MailChannels occupies.

Sales signal: WordPress care, rebuilds and managed hosting fit this base. Check the homepage first; a default title is a cheap way to spot a dormant site.

What MailChannels says, and what we see

MailChannels' pricing page invites readers to join millions of domains, and lists Outbound Filtering from $99.99 a month and a free Email API tier of 3,000 emails a month. We count 67,894 domains on the inbound filter alone. There's no conflict: that line is about email delivery, the relay and API side, which no MX record shows. The same page quotes a DreamHost system administrator on how far MailChannels cut their support tickets.

Sales signal: size MailChannels' host partners from SPF includes if you need the relay footprint; use this page only for inbound.

Key takeaways

1. 67,894 domains filter inbound mail through MailChannels; 8.84% of Email Security, fourth of 12.

2. DreamHost shows on 80.2% of them, and its help centre explains why: spam filtering on means MailChannels MX records.

3. 78.66% of matched companies have 1 to 10 staff; Brazil is the second country.

4. Exits follow hosting and mailbox moves, not rival gateways.

How to use this list

Segment by host first, then drop dormant WordPress installs. For the full list of 67,894 MailChannels domains with company, size and stack data, explore TechnologyChecker.io. Our guide to technology detection methods explains why an MX record and an SPF include count different customers.