[LoganDark]

I've tried self-hosting my mail server, but that means all my outgoing mail will go to Spam on all providers that use reputation-based filtering. In all cases I had SPF, DKIM and DMARC working perfectly, PTR records, etc. but it just doesn't matter. Even a Fastmail domain goes right to spam on my personal account, and they are very very established. It's just not worth it.

[dwedge]

I use a dedicated server and a vps for this, so I get around the residential IP reputation issue. The rest of the problems with deliverability are overblown. In 15 years of doing it on multiple servers, I've had one 2 month period where Gmail was spamming me and one month where Yahoo spammed me. In both cases it stopped without me changing anything, I've always suspected it's brief periods of anti-competition attempts which don't last forever

[LoganDark]

I never used residential IPs. Most ISPs don't even let you set PTR records on those. My problem was that any server at practically any provider would reuse an IP that previous customers have used to send spam in the past. For example you can't hope to send mail from a DigitalOcean IPv4 address without going to spam. Nor from Kamatera. There are probably a few more providers that are basically blackholed because they're so often used for spam. (I don't have experience with providers that don't offer IPv4.) I believe some providers even attempt to block outgoing mail.