Companies Using Hornetsecurity

Hornetsecurity changed hands ten months before this crawl. Our October 2026 crawl finds 44,890 domains whose MX record sends inbound mail to hornetsecurity.com, 39,735 of them matched to a company, and since December 2025 every one of those mailboxes is filtered by a Proofpoint business unit. The base underneath is distinctive: German, mid-sized, old and bought through partners.

Three rows, one owner

Proofpoint completed the acquisition on 8 December 2025 for $1.8 billion, seven months after announcing it on 15 May 2025. Its release describes Hornetsecurity as a Hanover company whose 12,000+ MSPs and channel partners serve more than 125,000 customers. In our Email Security table that makes three rows Proofpoint's: Proofpoint (56,902 domains), Hornetsecurity, and the top row labelled Microsoft Defender, whose record, ppe-hosted.com, is the MX host of Proofpoint Essentials (286,844).

The lines are now converging. In May 2026 Proofpoint formed an MSP Platform business unit around Hornetsecurity and launched 365 Total Protection in North America under the Proofpoint name, and it is moving Proofpoint Essentials partners onto that platform, with current prices held until the end of November 2026. Domains that move their filtering across would point their MX at Hornetsecurity's hosts and start counting on this page.

Sales signal: a Hornetsecurity account now has Proofpoint behind it. Expect Proofpoint's name in renewal conversations, and partners should expect the MSP programme to stay, since the release says the business unit continues to serve MSPs.

What the MX records show

Of 1,000 random domains we looked up on 15 October 2026, 998 still had a Hornetsecurity MX. The hostnames tell you the history. 798 used the main mx01 to mx04 hosts, 120 used vade-mx hostnames, 58 a Canadian cluster and 21 a US one. Vade, the French filter that joined Hornetsecurity in March 2024, now runs on Hornetsecurity's servers, and that's where much of the French base comes from. No hosting company bundles it: the websites in the same sample sit on Hetzner (99), IONOS (93), OVHcloud (71), Mittwald (60) and dozens of smaller German hosts.

Sales signal: the vade-mx hostname is a quick way to find former Vade accounts. They went through a rebrand and a change of owner in under two years, which is a natural moment to review the vendor.

Growth and exits

The chart reads 34,873 domains in June 2026 and 44,890 in October, with the biggest step into July. Most of that is our side: the domains we crawl turn over every month, dead sites out and new ones in, and our detection widens over time. Exits are what stand out. Only 948 domains have dropped Hornetsecurity since 16 March 2026, against 5,010 on Barracuda's larger base of 67,327. Of the 904 that left on every hostname, 594 now point their MX at Microsoft 365.

"Hornetsecurity loses domains at under a third of Barracuda's rate, and the few who go mostly don't pick another gateway. They let Microsoft 365 take the mail directly." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: displacing Hornetsecurity is slow work. The better opening is the firm deciding whether it needs a gateway at all.

The Mittelstand and the French wing

Germany holds 22,181 matched companies, 55.82% of the total, and German-speaking countries 23,704. France follows with 4,937. By size, 48.7% have 1 to 10 staff and 29.59% have 11 to 50, but 550 have more than 1,000, including Miele, KSB, CLAAS and MANN+HUMMEL. 36.06% were founded before 1990. Construction leads the industries at 7.83%, and machinery manufacturing (2.72%) makes the top five, which it doesn't on our Barracuda or Jellyfish pages. I sized the largest German groups: the biggest has 12 domains, BayWa r.e. 9, CEWE 8 and Miele 7. None is more than a rounding error on 44,890.

Sales signal: this is a list of thousands of separate German and French decisions, usually made with a partner. Localised campaigns through MSPs will reach more of it than a direct enterprise motion.

Switching: Barracuda in, Proofpoint out

Since March 2026, 49 domains moved their MX from Barracuda to Hornetsecurity, 14 of them in the last 30 days, and 11 went the other way. Another 11 moved from Hornetsecurity to Proofpoint, a move between two businesses that now share an owner. Twenty domains run Barracuda and Hornetsecurity together today, most likely mid-migration. Small numbers, but the direction is consistent: Hornetsecurity gains from Barracuda by more than four to one.

"Barracuda is the rival Hornetsecurity takes customers from. After the acquisition, the flow to Proofpoint is a transfer inside one company." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: European Barracuda customers are Hornetsecurity's likeliest new accounts. If you sell against Hornetsecurity, start there too.

The stack around it

WordPress runs on 49.55% of the domains in our stack sample and TYPO3 on 7.0%, Matomo on 6.32% next to Google Analytics on 33.85%. The DNS hosts are European: IONOS 10.19%, OVHcloud 5.44%, ALL-INKL 4.55%, Mittwald 1.67%. Mailjet (3.21%) and Brevo (2.54%) lead email marketing. Microsoft 365 shows on only 5.36%, because our signal reads the MX record and here it points at Hornetsecurity.

Sales signal: this base leans toward European hosts and privacy-minded tools. Data residency and GDPR answers belong in the first email. Our DMARC adoption statistics show where mail authentication stands more widely.

What Proofpoint says, and what we see

Proofpoint's release puts Hornetsecurity at more than 125,000 customers. We count 44,890 domains, about one for every three customers, and the gap has clear causes. Hornetsecurity sells backup and permission tools for Microsoft 365 that never touch a domain's MX record, and Vade's own March 2024 release describes API-based filtering for Microsoft 365, which also leaves the MX alone. Those customers are real but invisible to a DNS check, so our figure measures gateway customers only.

Sales signal: a domain without a Hornetsecurity MX can still be a Hornetsecurity customer. Before you write one off, check for Microsoft 365 add-ons the MX can't show.

Key takeaways

1. 44,890 domains, 5.85% of Email Security, eighth of 12; 998 of 1,000 sampled MX records still live.

2. Owned by Proofpoint since 8 December 2025, which now controls three rows of the category table.

3. 55.82% of matched companies are German; France's 4,937 come largely with Vade.

4. Low churn, and a gain from Barracuda of 49 domains to 11.

How to use this list

Split German and French accounts, flag vade-mx hostnames, and route through partners where you can. For the full list of 44,890 Hornetsecurity domains with company, size and stack data, explore TechnologyChecker.io.