- Sieve support. I can possibly help with this, as I already have homebrew Sieve enabled MDA using libsieve from GNU mailutils. It works, but only maildir is ssupported and it's a little kludgy.
I would rather not create my own fully featured LDA. Making someone else's LDA just use Dovecot's mail_save() and dovecot-auth would be better.
I support this concept :-)
(I have an LDA whose scripting language includes an embedded SIEVE syntax, and I do plan to make it dovecot-friendly once I get up some more steam for another round of working on it. See www.mvmf.org if you are curious; apologies if it's rude to mention it here again.)
Doing the actual mail saving should be simple, but I'm not exactly sure how the initialization would work. It would need to figure out where and how mails are stored (dovecot-auth's master socket would tell), and also read namespace settings from dovecot.conf.
Or at least derive their information in compatible ways.
mm