Companies Using Mailjet

Mailjet hardly ever shows up on a website. I took 250 random domains from our October 2026 list and checked them on 11 October: 244 carried include:spf.mailjet.com in their SPF record, and one showed a Mailjet signup form on its homepage. So this page lists domains that have authorised Mailjet to send mail for them, 139,573 in our October crawl, and we matched 107,775 of the 140,088 in our clean live set to a company, a 76.93% match rate. That's lower than Sage Intacct's 93.22%, per its profile, and it fits a product with a free plan that small senders sign up for.

What the SPF record proves

An SPF include tells receiving mail servers that Mailjet may send for the domain. Somebody with DNS access added it, so there was an account. It doesn't prove the account still sends, because nobody has to remove an include when they stop, and it misses customers who send from Mailjet's shared domain without touching DNS. The sample shows where the record sits too: 241 of the 244 includes were on the root domain and 3 on a subdomain only, while 6 of the 250 domains showed neither signal on the day.

Sales signal: treat 139,573 as a floor on accounts that once set up branded sending, with a stale tail. A domain that lists Mailjet and a second sender in SPF is the one to ask which tool does which job.

Growth trajectory

The chart reads 115,028 domains in June, 130,371 in July, 132,209 in August, 137,985 in September and 139,573 in October, a 21.34% rise in four months, with 15,343 of it in the first step. I wouldn't sell that as momentum. The set of domains we crawl turns over every month, with dead domains dropping out and new ones added, and our detection widens over time. Both lift a count like this without a single new signup. Exits are the other half: 3,342 domains have lost the signal since we began tracking it in March 2026, 2.39% of today's count, and 212 of them still carry it on another hostname. That's more movement than on Sage Intacct's verification key (67 of 7,116, per its profile). It fits a record admins do edit: SPF allows only ten DNS lookups, so old includes get pruned when a new sender goes in.

"Mailjet is close to invisible on a homepage and plain to see in DNS. Its count is every company that once wired Mailjet into its mail, and its churn is the minority who cleaned up afterwards." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: this is a large, stable, mostly European base, not a fast riser. Timing comes from the record itself: a domain that adds a second sender's include next to Mailjet's is in the middle of a decision.

Who the customers are

Small and young. 52.25% of matched companies with a known headcount have ten or fewer staff and 27.89% have 11 to 50, so 80.13% (81,318 of 101,477) employ 50 or fewer. Of those with a founding year, 49.39% started in 2010 or later (34.7% in the 2010s, 14.69% in the 2020s). The enterprise rows are real but thin: 2,656 companies have more than 1,000 staff. McDonald's, Gap Inc., Michelin, British Airways, Louis Vuitton and E.ON all carry the include on their root domain. At groups that size it probably covers one programme, a loyalty mailing or an event, rather than all company mail. Five rows on our top-50 list authorise Mailjet only on a subdomain, Carrefour's community site and Equinix's careers site among them, which makes the same point from the other side.

Sales signal: in the 1 to 50 band, the owner chose Mailjet and will choose its replacement. At the enterprise rows, find the team behind the include before you pitch; central marketing may not know it's there.

Countries and industries

France holds 35,176 of the 107,775 matched companies, 32.64%, more than three times the United States (10,699). Germany (10,235), the United Kingdom (6,709), the Netherlands (5,563), Spain (4,386) and Belgium (4,276) follow, so six European countries hold 66,345 companies between them. Mailjet, founded in 2010, bills from France: its pricing page quotes prices before French VAT. Its sister brand looks the other way, with Mailgun's profile led by the United States on 73,561 companies. Sinch completed its purchase of Pathwire, the parent of both, in December 2021. Industry is flat. Software Development (5.06%) and IT Services (5%) lead, and the top ten add up to only 33.55%.

Sales signal: anything sold on top of Mailjet, a deliverability audit or a CRM connector, needs French and German copy first. The US rows are a tenth of the base, not the core.

Rivals and switching

Mailjet holds 5.27% of Email Marketing, 7th of 73, with MailerLite 275 domains behind. Against the senders we measure the same way, from DNS alone, it's the smallest: Sendgrid has 344,723 domains, Mailgun 302,216 and Amazon SES 225,942. The two Sinch brands trade a little in both directions, 99 domains from Mailgun to Mailjet and 87 from Mailjet to Mailgun.

The switching table needs care, because most rows are co-presence: a domain with two senders' includes drops one. In 284 of the 304 "switched from MailChimp" rows, we'd seen both tools on the same domain first. Counting only rows where the new tool appeared after the old one went, Mailjet gained 20 domains from MailChimp and lost 3 to it, and lost 46 to Amazon SES while gaining 18 from it. Those numbers are small, and they're domains.

"Mailjet's switching story is a lean, not a wave. A few newsletter senders arrive from MailChimp, and a few more domains take their mail to Amazon SES than come back." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: for a competing sender, the opening is the domain with two includes, Mailjet plus Brevo or Sendgrid, which is already running two tools. For Mailjet partners, the domains adding Amazon SES are the accounts to watch.

The stack around it

Percentages here are of the 140,091 live domains in our clean set. WordPress builds 43.17% of the websites and Elementor 14.66%. WooCommerce (7.09%) is the most common shop, ahead of Shopify (2.6%) and PrestaShop (2.32%). Microsoft 365 handles company mail on 31.43% and Google Workspace on 18.37%. The European base shows in analytics and consent: Matomo runs on 5.69%, against 1.38% on Mailgun's profile and 1.44% on Sendgrid's, and five consent managers each sit between 2.85% and 5.23%.

Sales signal: WooCommerce and PrestaShop shops with Mailjet in DNS are the natural buyers of order and cart emails. Lead with those, not with newsletters, which they already send.

Key takeaways

1. 139,573 domains authorise Mailjet to send in October 2026, a floor on accounts, with 107,775 matched to a company.

2. A French-led European base: France has 35,176 matched companies, the United States 10,699.

3. Small and young: 80.13% employ 50 or fewer, and 49.39% were founded in 2010 or later.

4. Churn of 2.39% since March is real but low, because SPF includes outlive the sending.

5. Switching rows are mostly co-presence. The clean flows are small: in from MailChimp, out to Amazon SES.

How to use this list

Start with France, Germany and the Benelux in the 1 to 50 band, then split by industry. Software and IT services give you companies that send through the API; real estate and retail give you newsletter senders. A first line that works for a deliverability service: "Your domain authorises Mailjet and a second sender in SPF; we can tell you which one your customers' inboxes trust." If you sell on both sides of the Atlantic, set this list against Emma's, where 6,364 of 6,886 matched companies are in the United States; the two bases barely meet. For the full list of 139,573 Mailjet domains with company, size and stack data, explore TechnologyChecker.io.