Upgrading Stalwart from 0.15 to 016
The Setup
This is going to be a doozy of a post, but hopefully a wealth of information for someone out there. I think I may have ran into, literally, every issue that one could run into with the Stalwart 0.15 -> 0.16 upgrade path. I lost all my emails, went down reverse proxy rabbit holes, DKIM inconsistencies, sub-addressing changes, and just some strange behavior I was not expecting from various Stalwart features and logs. So stick around, this one will be good!