Dovecot LDA

To feed received messages to Dovecot for final delivery, there are two ways:

• Use a pipe transport. This is detailed in the Dovecot wiki. Note however that tainted values cannot be used on commandlines
• Use LMTP. For LMTP via a Unix-domain socket to a local Dovecot, use the lmtp transport; for LMTP over an IP socket (so Dovecot can be remote or local) use the smtp transport with protocol=lmtp. Dovecot docs here. This performs better the pipe option, as it does not need to start a fresh dovecot-lda process for every message.