Migration to FastMail
I have migrated my mail setup to FastMail. It removed the need to run my own mailservers with all the required infrastructure including webmail. I finished the migration a week before Christmas and should have not missed any mails.
Maintaining my own setup was a too high effort. Before FastMail I also tried G Suite (Gmail) but it does not have mail folders and would have required me to drastically change the way I read my mail.
The migration was done over IMAP interface, provided by the Dovecot-imap package. It took about an hour to transfer all 8000 messages. I'm using the Standard plan which is 50$ per year and which provides 25GB of space for mail.
Backups
I added a cron job to my backup server to backup the FastMail account automatically. It uses the offlineimap utility. Here is the article where I got the idea. The original article is about Gmail but it's easy to adopt to FastMail.
Servers
I have some servers that send out mail. I have configured them to send messages through my FastMail account SMTP. Here is an article how to set up Postfix to do it.