Hello to all,
one of the features that it's missing currently is the IMAP-Sieve, maybe I'm mistaken but Cloudron support only Sieve for SMTP connection/incoming email. https://doc.dovecot.org/configuration_manual/sieve/plugins/imapsieve/
Interesting, have not heard about this plugin before. https://doc.dovecot.org/configuration_manual/howto/antispam_with_sieve/#howto-antispam-with-imapsieve is also interesting to know (we use the antispam plugin).
I am not 100% sure what the use case is for this though.