I run a lot of homelab type services which send out emails as notifications. However, the issue I have is a simple one. I migrated to ProtonMail mainly on Peer pressure however I was using it a while back, and I wanted to make things a little more secure. If you’re looking for a well thought out free (for 5 domains) Mailserver I would strongly recommend Axigen. Up until last night I was hosting my own Axigen mail server for 3 domains running in a cloud-hosted VM. I also can’t spend hours working out certificates for other ports. I’m using port 25 as the mail relay is internal only, it’s not public-facing and it’s not needed to be encrypted.

I’m then going to use postfix as a mail relay on port 25 (not encrypted) to move mails through the ProtonMail bridge to my proton mail accounts. What I’m going to go through is to set up the ProtonMail Linux bridge in CLI mode as a service that will sit and listen on port 1025 for SMTP. You may read this title and think “That’s oddly specific” which to a degree it is. Bash, blog, homelab, howto, linux, selfhosted

Bridge protonmail