Self-hosting is tricky to get right and the cost of getting something wrong is high.
One more provider I haven't seen mentioned here is Zoho.com/Zoho.eu
They're more business-oriented, and they offer a whole suite of collaboration tools. They're one of the only providers I've seen that support custom domains in their free tier offering (https://www.zoho.eu/workplace/pricing.html)
It's not tricky, it's tedious. There's nothing tricky about it. You need a static IP, reverse DNS set to system hostname, "regular" DNS for the system hostname, DNS SPF entry, DKIM, DMARC, and authentication - it can get complex but it's quite straightforward.
On the other hand, things like iRedMail[^1] or Mail-in-a-Box[^2] will do most of the magic part for you.
> It's not tricky, it's tedious. There's nothing tricky about it. You need a static IP, reverse DNS set to system hostname, "regular" DNS for the system hostname, DNS SPF entry, DKIM, DMARC, and authentication - it can get complex but it's quite straightforward.
Plus you need to know a thing or two about linux administration, security, high availability (kinda, since short outages are tolerated by smtp), backups, spam, dealing with having your IP blacklisted and probably a few other things. Oh, and then there are the periodic updates, hacking attempts, vm reboots...
None of this is rocket science and it's probably fairly easy to get started, but it'll be hard to beat the security and reliability of a professionally managed service.
> None of this is rocket science and it's probably fairly easy to get started, but it'll be hard to beat the security and reliability of a professionally managed service.
Depends what kind of security, availability is a part of it. When you forget your password (or it gets hacked and someone changes it), you can just re-deploy the whole thing. On Gmail you might be screwed. On self-deploy backups seem mandatory, which mail user backs up his or her E-Mails?
As far as I have heard, if SPF, DKIM etc etc is properly configured, blocking won't happen. I don't have this running yet but this is my next project. Probably I'll go with postfix, there are bizillion plugins for exactly these things and the configuration will be automated with Ansible. So once it's up and running, I expect this to be pretty much care-free.
...and then you need to deal with all the blacklists. I once tried hosting an email server and found out at least one major American ISP was blacklisting everything from Digital Ocean. And when that happens, good luck reaching someone to get out of their list.
I would still call it tricky. I consider myself pretty capable but after a month of unsuccessfully tracking down DKIM/SPF/DMARC failures for some recipients I just gave up and switched to Fastmail.
I lasted just over a year of working at FastMail before I moved my personal stuff for my family over. I resisted for a bit - but I figured if I was getting in woken in the night to fix the FastMail system anyway, I might as well not be woken a second time if my family system went down!
One more provider I haven't seen mentioned here is Zoho.com/Zoho.eu
They're more business-oriented, and they offer a whole suite of collaboration tools. They're one of the only providers I've seen that support custom domains in their free tier offering (https://www.zoho.eu/workplace/pricing.html)