Re: Last Call: SMTP Service Extension for Secure SMTP over TLS to Proposed Standard

Keith Moore <[email protected]> writes:
> I've seen zero discussion of the extent of broken vs. conforming 
> implementations in groups that are frequented by SMTP implementors.
> All I've seen is your claim that most client implementations fail to 
> follow the spec in sending TLS 1.0 Hello messages.  No offense,
> but I don't think that's sufficient justification to change the spec.
I've just checked out a number of implementations:

qmail STARTTLS patch		       SSLv2 backwards compatible hello
Postfix STARTTLS patch		       SSLv2 backwards compatible hello
Sendmail 8.11			       SSLv2 backwards compatible hello
				       (turned off if you're not using
				       RSA).

The Sendmail STARTTLS page
(http://www.sendmail.org/~ca/email/starttls.html) claims
that CommuniGate Pro 3.3BetaX and Interchange v.3.61.01
support SSLv3 only. It's unknown--at least to me what
sort of ClientHello they send.

I don't have Exchange so I can't say what it does.

-Ekr