I second Fastmail wholeheartedly. I moved multiple self-hosted (Postfix and Dovecot) environments to Fastmail and haven’t looked back. The only thing I lost was

I second Fastmail wholeheartedly. I moved multiple self-hosted (Postfix and Dovecot) environments to Fastmail and haven’t looked back. The only thing I lost was the ability to manually configure an address to bounce back. Sending and receiving as a wildcard alias is fantastic, and Fastmail allowing that was the reason I finally moved. I held out on that feature for a long time. (You can also do this in Exchange Online if you want to run a convoluted and officially unsupported configuration.) I only twice had any kind of RBL issues, and one was a motivating factor in moving. I also got tired of worrying about patching and CVEs. I do that enough for my work.