“Run Your Own Mail Server” technology stack

I’ve churned through much of the general stuff about email, and am about to dive into specific configurations and examples. In some ways, the protocol background is the hardest part of any book. Orienting the reader to understand the configuration examples and make their own decisions is a pain–though front-loading the hard stuff simplifies writing the rest of the book.

But this means I need to make final decisions on the book’s technology stack.

Postfix (backed with MariaDB) and Dovecot are absolutely in, period. But there are dozens of implementations of DKIM and greylisting and antivirus, of varying sizes and inclusivity. Postfix supports the milter interface, so there’s an overwhelming pool of plugins. Options, options!

I’m leaning towards rspamd, and providing antivirus and dkim through it.

One of the core Unix philosophies is “many small tools that each do a single thing well.” Rspamd is easy, but it certainly isn’t small. How much difference is there between “plug ClamAV and SpamAssassin and greylisting and SPF and OpenDKIM and RBLs into Postfix’s milter interface” and “plug ClamAV and greylisting and SPF and DKIM and RBLs into rspamd’s interface and milter rspamd into Postfix”? Not a huge amount. Either way, you can see all the connections and have source code to all the tools.

Then there’s the web IMAP client. Today’s contenders seem to be Horde and Rainloop. Horde is heavier than necessary. The free version of Rainloop is nice, but it’s commercially backed and I worry about enshittification. I’m not predicting that they will turn on their customers, but including such products in a book has burned me. Many times.

Anyway, that’s where the book is and what I’m doing. The obligatory reminder that you can still sponsor RYOMS.