On Sun Jul 10 2011 Lars Magne Ingebrigtsen wrote:
> "Roland Winkler" <winkler@gnu.org> writes:
> 
> > Debugger entered--Lisp error: (gnutls-error #<process smtpmail> -48)
> >   signal(gnutls-error (#<process smtpmail> -48))
> >   gnutls-negotiate(:process #<process smtpmail> :hostname "foo.bar.com"
> :keylist nil)
> 
> Right.  It bugged out where I guessed it must have, so I think this is
> probably fixed now.  Could you check and report back?

I recompiled emacs from the trunk today. Unfortunately, emacs simply
hangs now. So I set debug-on-quit to t, which gave me the first
backtrace attached below.

Then I also tried your other suggestion

  (setq smtpmail-stream-type 'plain)

which resulted in the error

  Sending failed: 530 Must issue a STARTTLS command first

see the second backtrace.

Now I am using GNU Emacs 23.3.1 for sending this email.
So in that sense I am fairly confident that nothing is wrong with
the SMTP server I am using.

Roland