On 2025-01-12 at 14:59:27 UTC-0500 (Sun, 12 Jan 2025 14:59:27 -0500) Scott K via Postfix-users <skaplan...@gmail.com> is rumored to have said:
> Postfix with Dovecot which should be listening on port 587? YOU need to decide that. It's a question about what kind of system you want and what you want it to do for you. If you are building a mail server that acts as a public mail exchanger for one or more domains, you need Postfix listening on port 25, speaking SMTP. That's where remote servers connect. If you are building a mail server that acts as your delivered message store, to read messages that you've received, you need to use IMAP, which is Dovecot's core function, and that uses ports 143 and 993. Port 587 is for initial message submission, i.e. for end users to submit the messages they write. Because the mail submission protocol is defined as a restricted subset of SMTP, the most common practice is to have Postfix handle it. However, Dovecot can also perform that duty as documented at https://doc.dovecot.org/2.3/admin_manual/submission_server/ provided that you have a suitable "smarthost" through which Dovecot can relay submitted mail. That upstream system could be running Postfix or any other MTA, configured to allow the Dovecot machine to relay mail through it. If you want your mail server to do everything: accept mail from the world to your users, accept mail from your users to the world, and store your users' delivered messages, you need BOTH Postfix and Dovecot. For that sort of system one could theoretically have either one handling 587, but Postfix is most common for submission on port 587 simply because that is less complex than setting up submission for Dovecot if you've already got Postfix running. -- Bill Cole b...@scconsult.com or billc...@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
