For submission (since you were talking of 465 and 587) they are essentially equivalent - so long as you don't transfer messages on an in-clear channel. Enforcing that is trivial.
For MTA-MTA traffic on 25 you need to support in-clear, or you'll fail to receive quite a large percentage of mail. Obviously you should support STARTTLS also on 25, and there is no standardised TLS-on-connect MTA-MTA method. -- Cheers, Jeremy -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
