Same as it was a decade ago. Postfix and Dovecot on debian stable, SA and RBLs so you catch spam, DKIM and SPF so your emails don't go to spam. I've been runnin

Same as it was a decade ago. Postfix and Dovecot on debian stable, SA and RBLs so you catch spam, DKIM and SPF so your emails don't go to spam. I've been running my own mailservers for about a dozen friends for several years now, with no issues and maybe an hour of maintenance per month. The ISPmail tutorials are very good: https://workaround.org/ispmail https://workaround.org/ispmail