| > There are all kinds of invisible forces that you abutt that can be difficult to figure out This was my main experience, and all I did was try to set up the ability to simply send emails to myself (gmail) (and no-one else). Things like: this script crashed, or btrfs scrub finished + scrub results, and similar. The first thing I tried was just setting up a VM with postfix running on it locally with my residential ISP. I don't even remember what the error was for this scenario, but it was just totally dead in the water. Absolutely zero mail delivery. I think I eventually figured out it's because google defers to spamhaus, and spamhaus says residential IPs = hard no. That next thing I tried, and what I ended up doing, was writing a docker container that just runs an SSH port forward to jump from my local network to a digitalocean host, which is where another docker container runs postfix. I had done this bit once before, and I tried to just set up DKIM (since DKIM was, to my reading, basically bulletproof - why bother with SPF when you have real cryptographic identity assurance?). This led to weird error messages from google about my IP having a super low reputation. This was something I'd been worried about so I spent a bit of time trying to cycle my IP. But I eventually figured out it was just a bad error message and setting up SPF suddenly made my emails start delivering. My main ongoing issue is that I had to add all my sending addresses (things my internalhostnamehere@myrealdomain.com) to my contacts in gmail, otherwise there was like a 50% chance they'd just go to spam. I've been running this setup for about a year and it's still a coin toss whether emails will come through fine, or if they'll say "this would've gone to spam but it's in your contacts". When that happens, I check the DKIM and SPF status in "original message" in gmail, and gmail itself says they both passed. Absurd tbh. For my "not self-hosted but better than letting google own my digital identity" solution, since I use apple icloud+ or whatever it's called, I set up the SPF stuff to let me send+receive email from my custom domain, so while icloud could still scan my mail, at least if I get banned, I still own the actual domain and could move somewhere else. |
Outlook and Gmail are basically having opaque rules who can receive email and there is no process to get “whitelisted” on these receivers.