4mo ago

Self hosting email, what's the latest and greatest what FOSS can offer?

So, as the topic says, I'm going to set up a self hosted email service for myself, family and friends. I know that this one is a controversial topic around here, but trust me when I say I know what I'm getting into. I've had a small hosting business for years and I've had my share of issues with microsoft and others, I know how to set things up and keep them running and so on.

However, on the business side we used both commercial solution and a dirt-cheap service with just IMAPS/SMTPS and webmail with roundcube. Commercial one (Kerio Connect, neat piece of software, check it out if you need one) is something I don't want to pay for anymore (even if their pricing is pretty decent, it's still money out from my pocket).

I know for sure I can rely to bog-standard postfix+dovecot+spamassassin -combo, and it will work just fine for plain email. However, I'd really like to have calendar and contacts in the mix as well and as I've only worked with commercial solution for the last few years I'm not up to speed on what the newest toys can offer.

I'm not that strict on anything, but the thing needs to run on linux and it must have the most basic standards supported, like messages stored on maildir-format (simplifies migration to other platform if things change), support for sieve (or other commonly supported protocol) and contacts/calendar need to work with pretty much anything (android, ios, linux, windows, mac...) without extra software on client end (*DAV excluded, those are fine in my books). And obviously the thing needs to work with imaps, smtps, dkim and other necessities, but that should be implied anyways.

I know that things like zimbra, sogo and iredmail exist, but as mentioned, it's been a while since I've played with things like that, so what are your recommendations for setup like this today?

55 comments

For self-hosting, be mindful IP addresses have reputation scores and your IP needs to build them up positively. You need to have reverse DNS set, DKIM, SPF records etc for a more trusted reputation, domain reputation etc to not be flagged and sent to spam folders. I just got the $1/month Proton E-Mail for 10 addresses for 1 custom domain as I didn't feel like dealing with any of this with self hosting, but props for going the self-hosting route.
- ISPs often have SMTP relay servers. If you hook into that, your mail gets instant street cred.
  
  Amazon SES is good for this too. I use it in combination with postfix for the outbound mail. Granted it feels a bit like cheating on the whole self hosting part, at least for outbound. And I only started doing it in the past year of self hosting for 20 years. MS (Hotmail, Outlook, Office 365) was by far the biggest asshole in randomly denying delivery from my (well maintained reputation wise and well configured) outbound IP before switching to an SES relay. Fuck em, seriously. It’s not just about preventing spam, it’s clearly a strategy towards email dominance. Other big players are guilty of this too though.
- Yes, you're right. But to be honest, it only took me four weeks of perseverance and a few mails to the administrators of spam lists and I had no more problems with receiving and sending mail.
  If you set up your mail server correctly and also enter a postmaster address, you will be informed of any problem, no matter how small, and can address it promptly.
  I was surprised at how quickly and, above all, helpfully the staff at the spam list providers respond when you write to them politely and, if necessary, ask for more background information and best practices.
  It was definitely worth it for me and I would do the work and build up the knowledge again at any time. As a result, you have maximum freedom in configuration and extensive options for customizing your own workflow in dealing with emails.

You may have already read this but I always think back to this blog post about self hosted email:
TLDR;
Mail is not hard: people keep repeating that because they read it, not because they tried it
Big Mailer Corps are quite happy with that myth, it keeps their userbase growing
Big Mailer Corps control a large percentage of the e-mail address space which is good for none of us
It's ok that people have their e-mails hosted at Big Mailer Corps as long as there's enough people outside too
https://poolp.org/posts/2019-08-30/you-should-not-run-your-mail-server-because-mail-is-hard/
- My problem is what happens if my internet goes down when there's an important email or something. I suppose I could run it on a VPS just in case, but that's still not as reliable as an email service, nor is it necessarily cheaper.
  So I pay for Tuta email. It's €3/month, supports my custom domains, and generally works pretty well. My VPS costs €4.5/month, and I may get rid of it once my city finishes rolling out fiber because I only need it due to CGNAT. Neither is particularly expensive, but Tuta is really good value for what I get. If my family members want to join, costs will go up (€3/user), so I may consider switching if that happens.
  
  SMTP retries. It's resilient. If it fails a couple of connections it'll even let the other side know it happened and when it's going to retry. If it can't get it to you in a couple of days it'll let them know it was not able to deliver.
  The rest stands true, hosted Mail is dirt cheap and is more reliable I'm trying to host it in a non-professional capacity.
  
  You won't be able to host email on a residential IP - all of them are on a permanent blacklist. I understand the money argument - and it's a real argument - but host your own email is just so cool!
- You're not wrong about centralization being bad, but email is a pain in the ass at scale. Reputation, block lists, any downtime, client bullshit, infrastructure costs... about a hundred things can go wrong, and any one of them is a SPOF.
  Email being hard is not a myth, and saying it is dismisses a ton of legitimate concerns.
  
  You’re right, but we’re not talking about “at scale” here if I understood OP correctly. We’re talking about considering self hosting email for those who have the technical know-how to do so and obviously not on a rickety 2010’s desktop PC in your living room on consumer broadband as another commenter hinted at. Anything online “at scale” is always going to be harder than doing it on a small scale.
- Well, from personal (professional) experience Email is hard.

I've been using mailcow for about a year and i am very satisfied, it checks all your boxes and is easy to configure and deploy over docker.
- Just beat me to it...
  The one thing that they don't have yet last I updated, though they've been working on it for a while, is a prod ready LDAP/SSO connection. I had the dev branch working with Keycloak, but never got plain LDAP to function.
  
  @ShellMonkey I use the Generic OIDC option, havent tried LDAP.
- Mailcow-dockerized is bulletproof. Never had a problem with it and has been rock solid.
- Another container-based alternative in that space is Mailu.
- 3 years and counting here, I host my own company email and a couple of clients, 120 email accounts and only had one issue with a compromised account, limit each domain to 100 sended emails and I can catch spam emails with enough time before my vps provider notice anything
  
  when you say limit to 100 sended emails, do you have a limit of like 100 within 24 hours or 1 hour or something like this?
- I also use Mailcow with three domains (one business). No problems with it from day one. Updates run regularly and smoothly like clockwork. I am happy to recommend it to others.
  
  I am happy to recommend it to others.
  If they ever support non-Docker systems again, I might be curious. Right now, I couldn't even use that.
- Second this. Mailcow very easy to setup, though the docs could use improvement. This might have changed already.
  That said, I found it easier to pay for a domain and email service where they worry about reputation and random microsoft blacklists.
  
  Yeah, Microsoft are the worst. Even after doing all the proof of work (reverse DNS, DKIM, SPF, …) and registering for their spam prevention postmaster tools equivalent, I still found myself randomly blocked for delivery sometimes.

I've been playing with Stalwart-Email as a combined SMTP/IMAP server. Its open source and written in rust, still pretty early in development and I haven't played with it enough to give any real opinion on the pluses or minuses compared to other software, but its worth taking a look at.
- Stalwart is 95% awesome. What holds me back is, that Mails are stored in a Database and not Maildir. Maildir is insanely trivial to backup incrementally and to restore individual mails if necessary. That currently holds me on dovecot.
- I'm also using Stalwart! It just works!
- Currently using Stalwart after about a decade of using iRedMail. Stalwart's setup was such a breeze; I let out an audible laugh/noise when the install completed in the blink of an eye and had all the DKIM, DMARC, SPF, etc. settings available for config.
  Making some nice improvements with each release too, proper user management, etc. Definitely a fan. Looking forward to when they support CalDAV and CardDAV.

My stack is postfix, dovecot, slapd for accounts, SoGO for web mail, calendar and task and contact management. Syncs to my phone via davx and just works out of the box. It's multi domain and my small company even sells hosted email services.
Rspamd for anti spam and dkim. Use a free email testing service to confirm SPF etc are setup correctly.
Also make sure you have regular backups and up to date lets encrypt certificates.

Great plan! We need more independently hosted email. I’ve been self hosting email for 20 years. Still running Postfix and Dovecot, but don’t have all the features you’d like though. I just wanted to chime in that I’ve moved from spamassassin to rspamd. And I’m happy about that. Given your experience in the hosting business I think you’ll like rspamd. One thing I have changed since a few months is have outgoing mail go through Amazon SES. I moved hosting from Linode to Hetzner and that turned out to be not so great for outbound delivery reputation. I didn’t want to migrate back to Linode so I bit the bullet and compromised with SES. That has been really working well, but I admit it is a bit of a step back from fully self hosting.
- What's the benefit of rspamd over SA? I've used SA since I first setup my mail stack years ago, and it's been great. Cron jobs run nightly to train based on the contents of all the mailboxes' .spam folders, so it's only gotten better with time.
  Not judging, just curious.
  
  I believe the ISPMail tutorials I was following during my rebuild recommended it as the successor to self hosted anti spam. Touting better performance, written in C vs. Perl for spamassassin iirc. The tutorials may have indicated that SA was no longer actively maintained, but that may be a figment of my imagination. Better fact check all of this. But I’ve been very happy with rspamd’s web interface to see what’s going on with the process. There’s a great history view in the dashboard that helps you better understand why a message got flagged as spam. It helped me better fine tune white and blacklists for example. Supposedly it also has a rich module system to enable more advanced filtering techniques like LLM’s and whatnot. But I haven’t looked into that yet. Granted rspamd is also used by ISPs that have massive throughput. I’m definitely not in that category :p

I have Dovecot and Postfix running on Debian on a server in my closet. Works great for my needs
- Same (but arch btw). It uses the existing Let's Encrypt certificate from certbot --nginx. I did everything possible advised by mxtoolbox (Blocklists, DMARC, SPF, DKIM, LIGMA and whatnot). Some things are hard or impossible, but not really needed, like reverse dns or DNS SOA.
  
  Oh, I forgot to mention, I'm going to run the whole thing on a VPS, so I'll have access to proper reverse dns and all, so that's not an issue.
- I like exim a bit more but yeah. The dead simple solution is my goto. It can be tricky without any experience but there's a ton of information out there.
  And once you set it up your pretty good almost indefinitely.

You can do calendar and contacts separate from email. Try Radicale. I've been using it for years.

Check out Mail-in-a-Box

It doesn't answer your questions about calendar and contacts, but you might still find it interesting to take a look at this project:
https://maddy.email/
- I've been using Maddy for about a year. It's easy to set up and has been trouble free.

I have been using modoboa, my installation is fine as far as it goes, but coming up a little short technologically these days, and the upgrade path is total replace. If you have or install Docker on your server, there are poste.io and docker-mailsever,which both look good. Running your mailserver in a container or VM is almost essential, for security, and so you can blow it away and start over if you make a mistake.
Running an email server is not necessarily hard, but it is stressful: if you have other users, even family, they will take it for granted when it works, and complain loudly when it does not. Like any server that others use. But, beyond security, I have a certain stubborn geek machismo about it, it's a level of sysadmin above basic.

@IsoKiero I don't know about "latest and greatest", but your bog-standard solution seems about right; just add radicale into the mix, and you've got calendaring and contacts.

- The couple of domains have been running on my company so the userbase is already there, but as I'm shutting down the business side they need to move to something else. And I don't really care if users want to switch to something else, that's not my problem.

I like NixOS Mailserver

I've stuck with iredmail for years. Spin up a VM, grab the installer, and see how it performs for you.

Has anyone here used Mox? It looks interesting, but maybe a little immature.

Honestly, what I use is not what I would recommend. ;-) My own setup follows these directions (TL;DR: OpenBSD, as much OOTB OpenBSD software as possible, and Dovecot.)

I've been using Poste.io for about 2 years on a vps from Netcup. It has caldav/carddav built in. I also use Radicale and Baikal for caldav/carddav.

55 comments