OpenSMTPD
Ranked 9 of 9 mail servers by recommenders
Recommended as a simple, low-config mail server that runs well on small OpenBSD and Linux machines. Critics cite its security record, including a past remote root vulnerability.
Recommended as a simple, low-config mail server that runs well on small OpenBSD and Linux machines. Critics cite its security record, including a past remote root vulnerability.
13 people gave an opinion
- recommend it
- 9
- criticize it
- 4
- approval share
- 69%
Recommended in 3 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 9 people recommend itNeeds 10 or more, not met.
- 2.3 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 3 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Simple, minimal configuration
“no nonsense and configuration feels rather modern compared to the legacy stuff that's out there”
Comment from 19 May 2026 in “OpenBSD 7.9 Released” “runs out of the box with minimal config on very low ram kvms”
Comment from 19 May 2026 in “OpenBSD 7.9 Released” “OpenSMTPD is also an absolute breeze”
Comment from 2 Aug 2026 in “NetBSD 11.0 Released” Happy long-term use
“I'm happy with it. Been running OpenSMTPd for many years at this point, on both OpenBSD and Linux, and I have no complaints.”
Comment from 19 May 2026 in “OpenBSD 7.9 Released” “now happily running OpenSMTPd”
Comment from 25 Jan 2026 in “Deutsche Telekom is violating Net Neutrality” Default choice for simple mail
“when I need a simple MTA (which is to say, in almost all cases)”
Comment from 19 May 2026 in “OpenBSD 7.9 Released” “It is the best SMTP server for the majority of use cases.”
Comment from 19 May 2026 in “OpenBSD 7.9 Released”
What people warn about
Each mark is one comment
Past security vulnerabilities and CVEs
“if you look at the security track record of opensmtpd, you'll quickly see”
Comment from 16 Oct 2026 in “Big Fish: Exploiting a 37-Year-Old Kernel Bug in OpenBSD” “their SMTP server had a remote root RCE a few years ago”
Comment from 16 Oct 2026 in “Big Fish: Exploiting a 37-Year-Old Kernel Bug in OpenBSD” “where opensmptd hasn't (CVE-2020-7247)”
Comment from 30 May 2026 in “Openrsync: A BSD-licensed implementation of rsync, by the OpenBSD team”
Other mail servers people recommend
The four most recommended other mail servers, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Stalwart Mail Server | 27 | 4 | 87% | 10 | 3 mo3 owners | Approved |
| Postfix | 21 | 5 | 81% | 9 | 22 yrs4 owners | Approved |
| Dovecot | 18 | 1 | 95% | 11 | 15 yrs4 owners | Approved |
| qmail | 15 | 5 | 75% | 10 | — | Approved |
| OpenSMTPDThis page | 9 | 4 | 69% | 3 | — | — |
What people said
All 13 comments that mention it, newest first. Each links to the original comment.
“if you look at the security track record of opensmtpd, you'll quickly see”
“their SMTP server had a remote root RCE a few years ago”
“OpenSMTPD is also an absolute breeze”
“where opensmptd hasn't (CVE-2020-7247)”
“when I need a simple MTA (which is to say, in almost all cases)”
“Comes with spamd, pf, httpd, OpenSMTPD and others.”
“runs out of the box with minimal config on very low ram kvms”
“It is the best SMTP server for the majority of use cases.”
“I'm happy with it. Been running OpenSMTPd for many years at this point, on both OpenBSD and Linux, and I have no complaints.”
“no nonsense and configuration feels rather modern compared to the legacy stuff that's out there”
“I tried using OpenSMTPD a long time ago, shortly after it came out, but things were not stable enough.”
“it doesn't have proper support for authentication via LDAP”
“now happily running OpenSMTPd”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.