v0.3.0
This is kindda a HUGE rework. SMTP backend switched from SaMoToP to mailin-embedded, resulting in:
- LMTP support dropped (I hope just temporary);
- no need to write anything to files as whole processing is done in memory;
- this also means we can return status - whether message was sent, was there any errors etc, no internal queue exists now, SMTP server should handle queueing from now on;
- possibility to deny mail to unknown/unconfigured recipients.