On Wed, Jan 09, 2013 at 01:59:22PM -0600, Jim Graham wrote: [snip] > Btw, port 587 is one of those that I said are used for authentication, > as opposed to port 25 which is UNauthenticated.
See the SMTP AUTH verb. Anything you can do on those oddball ports, you can do on port 25. An SMTP host will negotiate authentication, message integrity, and privacy. Mind, some of them are bady set up and will always negotiate to "none of those, take it or leave it". :-P 465 is SMTP-in-TLS. In general X-in-TLS is deprecated; see "upward negotiation" and in particular the SMTP STARTTLS verb. 587 is SMTP on another port, called "submission", and I have no idea why anyone thought it was necessary. It's just a port on which the MTA speaks SMTP but is unwilling to serve until AUTH has been negotiated. 25 could have been configured the same way. RFC 6409 ยง9 sets forth arguments for separating MTA and MSA but I find those arguments very weak. -- Mark H. Wood, Lead System Programmer mw...@iupui.edu There's an app for that: your browser
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