You'll need a fixed IP address and the ability to have your ISP / hoster configure a sensible reverse DNS entry for that IP address that matches a forward DNS entry that points to the same IP address.
You should at least configure some DNS records to have a proper MX and SPF configuration, too. Your preferred search engine (e.g. Google / DuckDuckGo) is your friend.
For inbound spam filtering it makes sense to configure Spamassassin as a milter (=mail filter).
If you are a perfectionist, you should look into setting up DKIM for your mail domain.
If only there was a distro meant to do just this, preferably from a read only media like CD-R. (I pine for the good old days of Knoppix, Eee PCs, and psudoanonymous vBulletins.)
More like if you want there to be a chance in hell any recipient at a major provider ever receives your email.
Before setting it up, I would first do a blacklist check on the server's IP address. I would also avoid using any shared IP address, as that could cause long term problems.
Reputation is important, and is a combination of IP reputation, domain reputation, and mail volume. I don't have experience running a low-volume mail server, though I suspect that sending mail to people you already know, and making sure that it gets through to them would be helpful. (Ask them to remove it from spam/whitelist/etc.) The main challenge is to get mail accepted from Microsoft/Yahoo/Google. That accounts for 90%+ of recipients.
Is there a known good checklist to follow to set this up? I'm sick of Gmail, iCloud and Proton.
I just had to move it all in a hurry when my server died...
https://www.earth.org.uk/note-on-site-technicals-67.html#202...