On 1/27/11 8:41 AM, Paul Hoffman wrote: > On 1/27/11 8:12 AM, IETF Chair wrote: >> Originally, two ports were assigned for plain and over-TLS, which for >> HTTP mapped to two different URL schemes: http and https. >> >> Many people thought that this was a waste of a port, and the STARTTLS >> approach was developed. You say that it does not work in some cases, >> and you seem to be suggesting that we go back to the original way. >> >> Maybe it works in some cases and not others. Can we say which is which? > > In a word: no. We have very little operational experience, and where we > do, it gives conflicting results. Some mail client developers say that > POP and IMAP STARTTLS works fine, some say that it is unreliable and so > they just use the alternate ports. So I can say that having provided a large scale mail-service in a former life that we made it work for our customers. On the SMTP side on the virtually everyone has this working except those people that use 465, because the service you're talking to on 587 is fundamentaly the same one that's on 25. joelja-mac:tmp joelja$ telnet nagasaki.bogus.com 25 Trying 147.28.0.81... Connected to nagasaki.bogus.com. Escape character is '^]'. 220 nagasaki.bogus.com ESMTP Sendmail 8.14.4/8.14.4; Thu, 27 Jan 2011 17:28:24 GMT ehlo jaeggli 250-nagasaki.bogus.com Hello adsl-99-173-15-226.dsl.pltn13.sbcglobal.net [99.173.15.226], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 250-DSN 250-ETRN 250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN 250-STARTTLS 250-DELIVERBY 250 HELP > Note that Cullen's example for where it almost certainly would not work > is for non-stream UDP. Making UDP developers have to come up with a > stream-like capability to do a STARTTLS-style single port solution > defeats the purpose of using UDP. The benefit of "we saved another > port!" over "we forced someone to make UDP more like TCP!" seems like a > false one. > _______________________________________________ > Ietf mailing list > Ietf@xxxxxxxx > https://www.ietf.org/mailman/listinfo/ietf > _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf