On Fri, May 21, 2010 at 16:15, Charles Marcus <cmar...@media-brokers.com> wrote: > On 2010-05-21 4:04 PM, Phil Howard wrote: >> OK, I can do SMTP over TLS/SSL on port 465 (with a slight and unlikely >> risk of usage collision). So what is port 587 for? > > ? This question has been answered at least 3 or 4 times in this very thread. > > port 465 is for SMTP+SSL > this is DEPRECATED and has been for a long time > > port 587 is for SMTP+STARTTLS > this is the designated SMTP SUBMISSION port > > The submission port should always be used instead of port 465 unless you > must support older clients like Outlook Express and older versions of > Outlook that will only do SMTP+SSL over port 465.
I don't want to use port 465 because it isn't an unassigned port (though even unassigned has a risk that it could become assigned later on). But I need to use SMTP over TLS/SSL. It's not due to a client, but instead, due to networking (tunnelled TCP connections). It seems my choice is between using 465 or using some unassigned arbitrary port. Maybe 60025?
