Hi can proxmox mail gateway function as an email server as well or basically the end point where emails end up?
its more like on the small scale it doesn't make sense to separate things. For a small company i'd rather have 2 VPS with both combining mail server and PMG.Well... "PMG per se" indeed cannot do it, but... the underlaying system is Debian, so of course you may install extra software on the same server to achieve this goal.
For example install dovevot imap/submission server + extra add extra postfix instance on private port to work as MDA + add some kind of user database (like ldap, or at least static passwd file). It's doable and should not be very hard (if you know what you do...). On the other hand - it seems reasonable to separate mail proxy (PMG) and the main server. Or at least containerize one of them. (Or both...)
You don't need 2 "full" mail servers - one is enough (+2 pmg's). If you wish you might combine one pmg with mailserver, thus effectively you will have 2 vps.its more like on the small scale it doesn't make sense to separate things. For a small company i'd rather have 2 VPS with both combining mail server and PMG.
Thanks, no i don't combine everything. For instance what we use for our website is hard to containerise and on the small scale keeping it simple is hard to have multiple instances for, but mail is one of the things that can be easily replicated across multiple VPS thanks to DNS whereas a website not. I'm also thinking of combining with local as well, so there can be 2 mail servers in a good way, one in datacenter via provider and one in office which makes it cheaper to have more.You don't need 2 "full" mail servers - one is enough (+2 pmg's). If you wish you might combine one pmg with mailserver, thus effectively you will have 2 vps.
When your main server goes down - the other proxy will hold mails until the server goes back.
By the way: separation IS important even on small scale. My scale is really small, so i know what I say. When you combine too much services in one container/computer - upgrades become hard or even impossible.