offering (self)hosted email for ourselves and maybe others down the line #115

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opened 2026-10-06 11:48:29 +00:00 by jessebot · 0 comments

jessebot commented

2026-10-06 11:48:29 +00:00

Owner

Let's start by just experimenting with hosting it for ourselves on an inconsequential domain. I'll use this issue to write everything I know/learn about FOSS self-hosting email.

I asked about this on fedi, because why not. And oh boy, there were many more options and opinions on a lobste.rs post someone linked. I read all the responses and compiled everything below.

Full Email Suites

~~maddy~~
- It replaces Postfix, Dovecot, OpenDKIM, OpenSPF, OpenDMARC and more with one daemon with uniform configuration and minimal maintenance cost.
  Note: IMAP storage is "beta" and jmap is unsupported. If you are looking for stable and feature-packed implementation you may want to use Dovecot instead. maddy still can handle message delivery business.
mailcow
- selling point is docker images to wrap common stuff like postfix and rspamd
- using AI in their repos
~~mail in a box~~
- older and uses spamassisin - see below
mailu
- built for docker (combines dovecot, postfix, rspamd, webmail, and admin panel)
- doesn't support jmap and won't until dovecot does
mox
- (no milter / rspamd support, since spam hasn't really been a problem with mox https://github.com/mjl-/mox/issues/47)
- sponsored by nlnet
- jmap is on the roadmap
- AI in the codebase
Stalwart - New kid on the block that many are excited about, but not quite production ready yet. Some comments from lobste.rs:
- reports of LLM in the pro product
- reports of LLM generated docs that are frustrating and verbose but somehow incomplete
- JMAP is a major feature
- reports of upselling all over the place in the community edition
- groups support is limited?
- does its best to work out of the but you still need to troubleshoot things (use https://www.learndmarc.com/ to check your config).
- There are things like reverse DNS that Stalwart can't help you setup.
- One thing I'd like to improve later is having a jmap based syncing tool. Similar to mujmap.
inbuxa
- AGPL fork of stalwart aimed at being more free and no longer upselling or checking license keys
- written using AI
~~mok~~ "mail on kubernetes"
- seems to wrap postfix + dovecot
- developer commented and said they want to replace it with mox, but might still be useful to reference

Servers

MTA (mail transfer agent)

postfix
- seems to be the most common for sending mail?
- has a permissive ai policy (that allows major refactors)
Sendmail
- only mentioned once and seems to be predate postfix
courier
exim
- largely seems to have been superceded by postfix, but seems to be the original goto with some still using it
- has an anti-ai policy
OpenSMTPD
- seems to be mostly for BSDs (edit: but can also be run on linux)
- author note: I love the simplicity of opensmtpd, and the fact that it all runs without a database. Emails are stored as files and accounts are created with a dedicated passwd(5) like file in /etc/mail/.
- author note2: I followed https://poolp.org/posts/2019-09-14/setting-up-a-mail-server-with-opensmtpd-dovecot-and-rspamd/ back in 2020 and have been running it ever since. I wouldn't change anything.

Further reading: https://mailtrap.io/blog/postfix-sendmail-exim/

um these?

dovecot
- mentioned commonly in relation to both postfix and opensmtpd
- had an agents.md in their repo
james
- supports jmap
- no built in spam detection from what I can tell so far
- AI in the code base, but less than tmail
tmail
- fork/additions to james?
- uses claude

imap

cyrus primarily mentioned with postfix/exim
- its imapd but also supports jmap partially?
- has AI in the code base
imap-uw
- seemingly for openbsd?

Might be useful to look more into JMAP which seeks to replace imap, caldav, carddav

Server Security

Look into various DNSRBLs?

Spam filtering

~~spamassassin~~
- seems superseded by rspamd (but mentioned in relation to opensmtpd and postfix)
rspamd
- mentioned frequently in relation to both opensmtpd and postfix
- has a claude.md in the code base
postfix-policyd-spf-python - mentioned for postfix - checks spf records

greylisting specifically

greyfix - policy daemon for postfix, mentioned in relation to blocklistd, on codeberg
milter-greylist - mentioned in relation to sendmail and procmail
- not dead, it is just mature, and does not release often.
- milter-greylist is a stand-alone milter written in C that implements the greylist filtering method, as proposed by Evan Harris.
  Grey listing works by assuming that, unlike legitimate MTA, spam engines will not retry sending their junk mail on a temporary error. The filter will always reject mail temporarily on a first attempt, then accept it after some time has elapsed.
~~sqlgrey~~ - policy daemon for postfix, but source code not touched in over a decade

uncommon

~~spamd~~ (only mentioned in relation to opensmtpd so far)
blocklistd - mentioned in relation to postfix, greyfix, and openbsd

DKIM and DMARC

opendkim - sponsored by nlnet
opendmarc
~~dkimproxy~~ (only mentioned in relation to opensmtpd and does not seem to be active)

Mail list

mlmmj (for mail list) - mentioned only in relation to opensmtpd so far, seems old and not touched in 5 years

Clients

CLI/TUI

mutt - classic, defer to it since neomutt has AI in it
aerc
- anti-ai policy
- supports jmap
meli - anti-ai policy

local syncing and indexing

mbsync - synchronize imap4 and maildir inboxes
- msmtp - smtp client (combo also mentioned in relation to notmuch)
- mu (and mu4e) as agent, and msmtp to send.

bonus reading: https://ploum.net/2026-01-31-offline-git-send-email.html

Indexing

nomuch
- has an anti-ai policy
- While reading the mumap code and dependencies I was surprised to learn that notmuch is not thread safe
procmail

desktop

claws

Webmail

Android

k9mail
sterna

Let's start by just experimenting with hosting it for ourselves on an inconsequential domain. I'll use this issue to write everything I know/learn about FOSS self-hosting email. [I asked about this on fedi](https://social.open.engineering/@jessebot/statuses/01M46G3HBEZBKBBSHYHWEHYETR), because why not. And oh boy, there were many more options and opinions on a [lobste.rs](https://lobste.rs/s/rwloew/email_self_hosters_what_are_you_using) post someone linked. I read all the responses and compiled everything below. # Full Email Suites - <strike>[maddy](https://maddy.email/)</strike> - It replaces Postfix, Dovecot, OpenDKIM, OpenSPF, OpenDMARC and more with one daemon with uniform configuration and minimal maintenance cost. Note: IMAP storage is "beta" and jmap is unsupported. If you are looking for stable and feature-packed implementation you may want to use Dovecot instead. maddy still can handle message delivery business. - [mailcow](https://mailcow.email/) - selling point is docker images to wrap common stuff like postfix and rspamd - using AI in their repos - <strike>[mail in a box](https://github.com/mail-in-a-box/mailinabox)</strike> - older and uses spamassisin - see below - [mailu](https://github.com/mailu/mailu) - built for docker (combines dovecot, postfix, rspamd, webmail, and admin panel) - doesn't support jmap and won't until dovecot does - [mox](https://www.xmox.nl/) - (no milter / rspamd support, since spam hasn't really been a problem with mox https://github.com/mjl-/mox/issues/47) - sponsored by nlnet - jmap is on the roadmap - AI in the codebase - [Stalwart](https://stalw.art/) - New kid on the block that many are excited about, but not quite production ready yet. Some comments from lobste.rs: - reports of LLM in the pro product - reports of LLM generated docs that are frustrating and verbose but somehow incomplete - [JMAP](https://jmap.io/) is a major feature - reports of upselling all over the place in the community edition - groups support is limited? - does its best to work out of the but you still need to troubleshoot things (use https://www.learndmarc.com/ to check your config). - There are things like reverse DNS that Stalwart can't help you setup. - One thing I'd like to improve later is having a jmap based syncing tool. Similar to [mujmap](https://github.com/elizagamedev/mujmap). - [inbuxa](https://git.coffeylabs.org/inbuxa/inbuxa-server) - AGPL fork of stalwart aimed at being more free and no longer upselling or checking license keys - written using [AI](https://coffeylabs.org/ai/) - <strike>[mok](https://artifacthub.io/packages/helm/si-gitops/mok)</strike> "mail on kubernetes" - seems to wrap postfix + dovecot - developer commented and said they want to replace it with mox, but might still be useful to reference # Servers ## MTA (mail transfer agent) - [postfix](https://en.wikipedia.org/wiki/Postfix_(software)) - seems to be the most common for sending mail? - has a permissive ai policy (that allows major refactors) - [Sendmail](https://en.wikipedia.org/wiki/Sendmail) - only mentioned once and seems to be predate postfix - [courier](https://www.courier-mta.org/) - [exim](https://en.wikipedia.org/wiki/Exim) - largely seems to have been superceded by postfix, but seems to be the original goto with some still using it - has an anti-ai policy - [OpenSMTPD](https://en.wikipedia.org/wiki/OpenSMTPD) - seems to be mostly for BSDs (edit: but can also be run on linux) - author note: I love the simplicity of opensmtpd, and the fact that it all runs without a database. Emails are stored as files and accounts are created with a dedicated passwd(5) like file in /etc/mail/. - author note2: I followed https://poolp.org/posts/2019-09-14/setting-up-a-mail-server-with-opensmtpd-dovecot-and-rspamd/ back in 2020 and have been running it ever since. I wouldn't change anything. Further reading: https://mailtrap.io/blog/postfix-sendmail-exim/ ## um these? - [dovecot](https://doc.dovecot.org/2.4.5/) - mentioned commonly in relation to both postfix and opensmtpd - had an agents.md in their repo - [james](https://james.apache.org/) - supports jmap - no built in spam detection from what I can tell so far - AI in the code base, but less than tmail - [tmail](https://github.com/linagora/tmail-backend) - fork/additions to james? - uses claude ## imap - [cyrus](https://github.com/cyrusimap/cyrus-imapd) primarily mentioned with postfix/exim - its imapd but also supports [jmap partially](https://www.cyrusimap.org/imap/download/installation/http/jmap.html#jmap-implementation-status)? - has AI in the code base - [imap-uw](https://github.com/uw-imap/imap/blob/master/README.md) - seemingly for openbsd? Might be useful to look more into [JMAP](https://jmap.io/) which seeks to replace imap, caldav, carddav ## Server Security Look into various [DNSRBLs](https://en.wikipedia.org/wiki/Domain_Name_System_blocklist)? ### Spam filtering - <strike>[spamassassin](https://spamassassin.apache.org/)</strike> - seems superseded by rspamd (but mentioned in relation to opensmtpd and postfix) - [rspamd](https://github.com/rspamd/rspamd) - mentioned frequently in relation to both opensmtpd and postfix - has a claude.md in the code base - [postfix-policyd-spf-python](https://pypi.org/project/pypolicyd-spf/1.3.2/) - mentioned for postfix - checks spf records #### greylisting specifically - [greyfix](https://codeberg.org/KMK/greyfix) - policy daemon for postfix, mentioned in relation to blocklistd, on codeberg - [milter-greylist](http://hcpnet.free.fr/milter-greylist/) - mentioned in relation to sendmail and procmail - not dead, it is just mature, and does not release often. - milter-greylist is a stand-alone milter written in C that implements the greylist filtering method, as proposed by Evan Harris. Grey listing works by assuming that, unlike legitimate MTA, spam engines will not retry sending their junk mail on a temporary error. The filter will always reject mail temporarily on a first attempt, then accept it after some time has elapsed. - <strike>sqlgrey</strike> - policy daemon for postfix, but source code not touched in over a decade #### uncommon - <strike>spamd</strike> (only mentioned in relation to opensmtpd so far) - [blocklistd](https://man.netbsd.org/blocklistd.8) - mentioned in relation to postfix, greyfix, and openbsd ### DKIM and DMARC - [opendkim](http://www.opendkim.org/) - sponsored by nlnet - [opendmarc](https://github.com/trusteddomainproject/OpenDMARC) - <strike>dkimproxy</strike> (only mentioned in relation to opensmtpd and does not seem to be active) ## Mail list - [mlmmj](https://github.com/v12mike/mlmmj) (for mail list) - mentioned only in relation to opensmtpd so far, seems old and not touched in 5 years # Clients ## CLI/TUI - [mutt](https://en.wikipedia.org/wiki/Mutt_(email_client)) - classic, defer to it since neomutt has AI in it - [aerc](https://sr.ht/~rjarry/aerc/) - anti-ai policy - supports jmap - [meli](https://meli-email.org/) - anti-ai policy ### local syncing and indexing - [mbsync](https://isync.sourceforge.io/mbsync.html) - synchronize imap4 and maildir inboxes - [msmtp](https://marlam.de/msmtp/) - smtp client (combo also mentioned in relation to notmuch) - mu (and mu4e) as agent, and msmtp to send. bonus reading: https://ploum.net/2026-01-31-offline-git-send-email.html ### Indexing - [nomuch](https://github.com/aclements/notmuch) - has an anti-ai policy - While reading the mumap code and dependencies I was surprised to learn that notmuch is not thread safe - [procmail](https://en.wikipedia.org/wiki/Procmail) ## desktop - [claws](https://www.claws-mail.org/) ## Webmail - [sogo](https://www.sogo.nu/) - [Roundcube](https://roundcube.net/) ## Android - k9mail - [sterna](https://codeberg.org/emon/sterna-mail)

jessebot self-assigned this

2026-10-06 11:48:29 +00:00

jessebot added this to the Path to Hosting Email project

2026-10-06 11:49:35 +00:00

jessebot changed title from ~~offering hosted email~~ to offering (self)hosted email for ourselves and maybe others down the line

2026-10-07 08:13:01 +00:00