Companies Using Barracuda

Barracuda's customer base looks like the textbook buyer of a mail gateway: mid-sized, American and long established. Our October 2026 crawl finds 67,327 domains whose MX record sends inbound mail to Barracuda, 58,495 of them matched to a company. For a seller, the most useful thing in this data is where the leavers go.

What the MX record shows

Barracuda's setup documentation gives each protected domain its own hostname under ess.barracudanetworks.com, and in our sample that held: 980 of 1,000 random domains still had a Barracuda MX on 15 October 2026, and no two shared a hostname. The hostnames also name the data centre. 707 used the default cluster, 116 the UK one, 98 the German one, 37 Canada's, 19 Australia's and 3 India's. What the record can't show is Barracuda's API deployment for Microsoft 365, which its plans page offers alongside the MX change. Those customers keep Microsoft's MX, so treat 67,327 as a floor.

Sales signal: the regional hostname is a free routing hint. A UK or German cluster shows where the customer wants its mail processed, which shapes the pitch.

A step, then steady exits

The chart reads 58,000 domains in June 2026 and 67,327 in October, with steps into July and September. Most of that is ours: the domains we crawl turn over every month, dead sites out and new ones in, and our detection widens over time. The exits are the real movement. 5,010 domains have dropped Barracuda since 16 March 2026. Of the 4,819 that left on every hostname, 3,332 now point their MX at Microsoft 365, mail going straight to Microsoft with no gateway in front, and 63 at Google Workspace.

"Barracuda's biggest competitor in our data is Microsoft 365 with nothing in front of it: two in three leavers now take their mail straight there." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: a Barracuda renewal is often a debate about whether a separate gateway is needed at all. Lead with what Microsoft 365's own filtering misses, not with feature lists.

Who the customers are

52.93% of matched companies with a known size have 11 to 200 staff, and 1,404 have more than 1,000, from Tupperware and Ternium to Mankind Pharma and Huhtamaki. 43.55% were founded before 1990. Construction leads the industries at 7.3%, and health, finance, insurance and law together reach 14.58%. School districts are a visible group: Baltimore County, Henrico County and Cleveland Metropolitan all route mail through Barracuda. Geographically it's an English-speaking base, 48,801 matched companies in the US, UK, Canada, Australia and Ireland, with an unusual Benelux slice of 2,864.

Sales signal: these firms have an IT person or an outside provider and often regulated data. References from the same industry beat discounts.

The MSP question

Barracuda runs a programme for managed service providers, so I looked for reseller clusters. There aren't any visible from outside. The MX hostnames carry a per-domain number, not a reseller name, and the nameservers of our 1,000 sampled domains point at GoDaddy (235), Cloudflare (193) and Network Solutions (75), with no MSP-run DNS cluster above a handful. Owner groups are small too: the largest has 7 domains. Which MSP manages a given Barracuda customer isn't something DNS tells you.

Sales signal: prospect Barracuda accounts one company at a time. If you sell to MSPs, the list tells you their end customers exist, not who manages them.

Switching: Proofpoint, Mimecast and Microsoft

The published switching rows lean hard against Barracuda. Since March 2026, 226 domains moved to the row labelled Microsoft Defender, which reads ppe-hosted.com, the MX host of Proofpoint Essentials, while 99 came back. 182 went to Mimecast against 61 returning, 78 to Proofpoint's enterprise gateway against 10, and 49 to Hornetsecurity against 11. Hornetsecurity joined Proofpoint in December 2025, so 353 of the 550 published departures landed on a Proofpoint-owned gateway. Even so, those rows are small next to the 3,332 domains that went straight to Microsoft 365.

"Count the gateway destinations by owner, and Proofpoint takes far more of Barracuda's departing domains than Mimecast does." - Elif Arslan, CMO & Co-founder at TechnologyChecker.io

Sales signal: Proofpoint Essentials takes more Barracuda domains than any other gateway. If you compete with it, the domains that run both today (87 with the Essentials row, 67 with Mimecast) are mid-migration and worth a call this quarter. Proofpoint is also moving Essentials partners onto Hornetsecurity's 365 Total Protection, so some of those domains may next show up under Hornetsecurity.

The stack around it

Google Analytics runs on 63.27% of the domains in our stack sample and WordPress on 50.84%, with WP Engine hosting 8.78%. GoDaddy shows on 27.76%, mostly as the DNS provider. Microsoft 365 appears on only 6.15%, where an outlook.com MX sits next to Barracuda's; a tenant behind the gateway can't show in an MX check. SendGrid (4.92%), Mailchimp (4.23%) and Mailgun (3.33%) handle outbound sending for a fair share.

Sales signal: these sites carry sending services and marketing tags, so deliverability and DMARC work is a natural second conversation. Our DMARC adoption statistics give the wider picture.

The link-protection side door

Barracuda's rule has a second clause, a script loaded through linkprotect.cudasvc.com. That's the host Link Protection rewrites email links to, and Barracuda's documentation says rewritten URLs don't expire. So when someone copies a tracking script's address out of an email into a website, it keeps loading through Barracuda; one site we checked loads Facebook's pixel that way. We found the pattern on 401 domains. 145 also have a Barracuda MX; 256 don't, 0.38% of the count, too few to move any figure here.

Sales signal: treat linkprotect-only domains as someone else's Barracuda customer emailing them, not as an install.

Key takeaways

1. 67,327 domains, 8.77% of Email Security, fifth of 12; 980 of 1,000 sampled MX records still live.

2. Mid-sized and old: 52.93% have 11 to 200 staff, 43.55% were founded before 1990.

3. Leavers mostly go straight to Microsoft 365 (3,332); among gateways, Proofpoint-owned products take 353 of 550 published departures.

4. MSP relationships don't show in DNS; prospect by account.

How to use this list

Filter by region cluster and industry, then flag domains that already show a second gateway. For the full list of 67,327 Barracuda domains with company, size and stack data, explore TechnologyChecker.io.