Of course it is. I've been running my for ages; the current setup is postfix, dovecot, dspam, opendkim, opendmarc. The last IP change was ~1 years ago, the last

Of course it is. I've been running my for ages; the current setup is postfix, dovecot, dspam, opendkim, opendmarc. The last IP change was ~1 years ago, the last domain change is ~1 month, no issues. A long while ago, when I wasn't running the mail server in lxc, and it was a server which also hosted web frontends, I got it "hacked" once; a rouge perl script sent 10s of thousands of emails within an hours. Thankfully, this was in ~2007, so removing the node from blacklists wasn't impossible. Anyway: add dmarc, and make sure you have TLS to send/receive. This latter is probably the most important bit.