Tony Finch wrote:
The reason that message submission is done with SMTP is because of the number of SMTP extensions that the MUA will want to use, in particular DSNs, deliver-by, deliver-after, message tracking, and whatever else may be invented in the future. If you want to make message submission a part of IMAP and POP then you'll have to re-do all these SMTP extensions twice, which is a colossal waste of time.
Not really - what I'm proposing is that the IMAP connection just pipe the message into an SMTP server. The IMAP is acting only and an authenticated connection back to SMTP. I'm not suggesting replacing SMTP. What I'm suggesting is that POP/IMAP can be used as a transport to get the mail there because it's an existing connection, is already established, is already authenticated with the credentials of the email account, and it isn't a port that people would block like port 25 is.
I'm not trying to replace SMTP. I'm just trying to suggest a better way for end users to get outgoing email to the SMTP server.
