I’ve set up a https://stalw.art server recently, and I’m quite impressed. I appreciate that the entire mail service stack is taken care of by a single unified service, except webmail but Bulwark seems really solid. It also works nicely together with Postgres and S3, so I can have the same backup strategy as most other apps I’m hosting.
First and foremost for the outgoing needs of https://nord.pub, but I’m seriously considering moving personal domains to it as well.
For infrastructure I’m using dedicated Hetzner hosts, with extra IPs for the mail servers, so that reverse DNS is consistent.
Largest problem I’ve seen is that Outlook.com is classifying the emails as spam, even with SOF, DKIM, DMARC properly set up… which is a big reason I’m hesitant to move all personal email as well. I realised that it could be a problem if I ever want to contact companies who use Office 365, which is a lot.