authinfo with smtpmail-auth-credentials

[Andrew Raines]

If I set smtpmail-auth-credentials explicitly like below, I
can send mail through my SMTP AUTH host.

  (setq smtpmail-auth-credentials
             '(("mail.host.dom" 25 "username" "password")))

However, if I let it default to "~/.authinfo," where I've set
up an entry for mail.host.dom, I get a protocol error.  I
assume that just means that authentication failed.  Are any
of you using .authinfo successfully with SMTP AUTH?  I'm also
using TLS, but that doesn't seem to affect this issue.

-- 
    aaraines@pobox.com (Andrew A. Raines)