Not sure why someone would go through the pain of cobbling up a self hosted solution based on Postfix when you have fully integrated solutions like https://stalw.art/, which are a breeze to setup.
Postfix has been around for decades and respects the Unix philosophy of doing one thing and doing it well. It's perhaps the most widely deployed MTA, and as such it has been thoroughly field tested.
Also, people in the FOSS community tend to be wary of "open source" projects primarily developed by a commercial company under dual licensing.
I am basically all in on Stalwart right now, but do not have the time to deal with email deliverability issues or asking my VPS to open a port, so I have been using AWS SES as the SMTP relay for awhile. No problems so far, hosting about a dozen mailboxes for friend's and family's personal use. The whole stack is so lightweight, I have it on the cheapest Arm-based VPS at Hetzner.
My hope is that Stalwart will get to their webmail project over the next couple of years. I am on SnappyMail, but basically need to use desktop and mobile clients to get the full mail/CardDAV/CalDAV experience, which admittedly is already pretty awesome.
Currently, I have Stalwart, PostgreSQL, SnappyMail, and Caddy, all inside a docker-compose file, and I have migrated, moved servers, and all that no problem.
I came to this thread purely to see if I was the only enlightened one.
Stalwart is perfect for small self-hosters: a single binary, a single-directory resilient datastore (by default), a UI for every setting, and defaults that guide you to a DNS config which maximizes your sender score. Plus support for all of the "power user" features such as ManageSieve and shared CalDav folders.
Honestly, I love hosting my email now. And the last remaining battery which could possibly be included is now WIP: webmail!
Unix philosophy need not apply when there is exactly one use case for integrating these tools. (Or at least, one case which covers 99% of users. The remainder can keep their managerie of arcane config formats and susceptibility to unsafe language CVEs.)
