Breaking is mostly self-inflicted. I followed the 123qwe.com version of the ISPmail tutorial, but made some changes to fit in with my aged Nextcloud setup. Th

Breaking is mostly self-inflicted. I followed the 123qwe.com version of the ISPmail tutorial, but made some changes to fit in with my aged Nextcloud setup. This caused a few hiccups. Changes were -- mysql not postgres, allowing mail logins by username as opposed to email address. The other problems I've had were * Mr Tutorial likes really tight TLS restrictions but some of my mail clients can't cope with them. * Turned on IPv6, had correct reverse DNS but forgot to put the v6 address in my SPF record. DMARC said "be strict" so gmail started rejecting my email. * Random markings-as-spam by gmail. This seems to be slowing down. * I've got the Dovecot xapian plugin but it doesn't feel like it's making searches faster. Need to make sure my IMAP client is actually doing server-side searches though! * Turned on port 465 (TLS submission), cannot get it to work so still doing STARTTLS on port 587 Also I knew that exim system inside out, I felt I really understood how exim processed mail. Now I don't have the time to learn postfix inside out in the same way. Oh to be an eternal university student again... One thing that has helped is the trick I worked out a few years back of hosting everything inside an lxc container on btrfs. I can snapshot and backup the whole system including database. Moving to a new hosting company means building another minimal debian system and rsyncing the container over. Borg backup of snapshots gives me confidence they can be restored, I'm not going to be backing up a database file while it's being written to. Moving my gmail over was the biggest pain, due to gmail being labels-not-folders. Spent quite a lot of time on some python code to spider my email and apply rules to remove duplicate messages. Lots of corner cases pop up there.