I can totally understand the pain involved in setup. I have done the same with postfix+dovecot for our outgoing email servers and we now have 8 outgoing and 1 +

I can totally understand the pain involved in setup. I have done the same with postfix+dovecot for our outgoing email servers and we now have 8 outgoing and 1 + 2 backups incoming allowing us to reboot for updates without losing too much capacity. I agree that the setup is a complete PITA but to be fair, postfix, at least, is very old and didn't have the benefit of what we've learned about best-practice configuration like having a single conf.d directory so things sit alongside each other nicely. The documentation is also very terse but Wietse did tell me that he's busy enough maintaining the software and porting all the docs is a mammoth task. I did do something myself converting the text files to markdown and using a SSG but there is too much stuff that I didn't understand well enough to re-word. There are also a tonne of compatability which has been added over the years which is no longer needed but still makes the docs feel a little overwhelming. My top-tip though, is to invest time in the Ansible setup script to avoid the scourge of following out-of-date blog posts line by line. We got to the point where we can provision a new server (manually) run the script and have everything setup ready to go, which is super helpful. The other important part is to monitor what is happening. Blacklisting can come upon you quickly and not always for an obvious reason but if you don't notice, it might be harder to resolve later and you might have lost a tonne of email. Instead, I semi-regularly spot an error in a log file and have to email someone or login to some ancient web page to request removal from a blocklist. We are generally always successful but it is also worrying that we have no direct control over it.