If you watch the protocols, one difference should become apparent.
With SMTP, after the `.' concluding the `DATA' command, you'll only
get one response, no matter how many recipients were listed for that
message. However, with LMTP, you get a response for each recipient,
in the order that the recipients were listed. That way you know
which recipients were able to receive the message, and which weren't.
Since Cyrus supports quotas, consider a situation where all but one
of the recipients were over quota. Why should that one that's not
over quota see the same message several times as the MTA attempts
redelivery to those that are over quota?
--
Amos
On Wed, 13 Dec 2000, Scot W. Hetzel wrote:
> LMTP will send the message only once to cyrus and allow cyrus to deliver the
> message internally to the list of recipients provided during the LMTP
> exchange with sendmail. One nice feature that this provides to cyrus is
> single-message store, where the message is stored in the first recipients
> mailbox, and the remaining recipients are hardlinked to this message, thus
> saving space on the server.
