Earlier quoted context omitted.
I ran multiple mail servers for years until about 10 years ago (moved out of the industry). The deliverability problem, as far as I know, hasn't really changed that much in the last decade. The key was to configure DKIM, SPF, only use secure protocols and monitor the various black/block-lists to make sure you aren't on them for very long. In my experience, if you end up on a few bad lists, and don't react quickly, th…
> It's not "plug-and-play", but it's not that hard. Once you've got it up and running the maintenance load goes to almost zero. This is where I disagree. In my opinion it might not be that hard but the maintenance is really not zero as you just described how you need a reputable IP as a prerequisite and constant monitoring of block lists. Just having DKIM, SPF and DMARC really was not enough last time I checked for g…
If you're a domain that only receives occasional messages, and you end up on Spamhaus and co, you're gonna have a problem. It seems that reputation at small scale is viral. You need actively good reputation and response time. But, honestly, it seemed that it didn't take more than about 3 months per domain I administered until they were just accepted by the net as valid, good actors.