SMTP Suddenly Not Working

[Purgatori Sakkara <purgatori.sakkara@gmail.com>]

Hi,

I have no idea why, but I am suddenly unable to use my ISP's smtp
server with Emacs. I haven't changed anything in my .emacs, and my ISP
claim not to have changed anything on their end, either. Feeding the
same settings into other applications -- e.g. Sylpheed -- results in
being able to send outgoing email just fine.

Here's my setup in .emacs:

   (setq smtpmail-smtp-server "smtp.netspace.net.au")
   (setq smtpmail-smtp-service 25)
      (setq smtpmail-debug-info t)
   (setq smtpmail-debug-verb t)
   (setq send-mail-function 'smtpmail-send-it)
   (setq message-send-mail-function 'smtpmail-send-it)
   (require 'smtpmail)
   (setq mail-host-address "sdf.lonestar.org")
   (setq user-full-name "My Name")
   (setq user-mail-address "username@sdf.lonestar.org")
   (setq mail-archive-file-name (expand-file-name "~/Mail/outgoing"))

   (setq gnus-always-read-dribble-file t)
   (setq mm-discouraged-alternatives '("text/html" "text/richtext"))
   (setq gnus-message-archive-group
      '((if (message-news-p)
            "sent-news"

          "sent-mail")))
  (setq message-kill-buffer-on-exit t)


Upon trying to send an email, I get "process smtp is not running,"
while the trace contains the following:

220 icp-osb-irony-out4.iinet.net.au ESMTP
250-icp-osb-irony-out4.iinet.net.au
250-8BITMIME
250-SIZE 31457280
250-STARTTLS
250-AUTH PLAIN LOGIN
250 AUTH=PLAIN LOGIN
220 Go ahead with TLS

Process smtpmail connection broken by remote peer
QUIT

... and I don't have any idea what that means. The weird thing is, it
started playing up last night, but during repeated tests I was able to
get *some* mail to go through. Now, though, it's not working at all.
Very bizarre.