>>> "Uwe" == Uwe Brauer <oub@mat.ucm.es> writes:

> Hi

> For gmail the following setting works (which I also use in
> thunderbird)
> (setq smtpmail-auth-credentials '(("smtp.gmail.com" 587 "user" nil))) 


> However when I set  

>      (setq smtpmail-auth-credentials '(("mail.gmx.de" 587 "user" nil))) 

I tried also 

(setq smtpmail-auth-credentials '(("mail.gmx.de" 587 "user" nil)))

Which works with 

gnutls-cli --insecure -p 587 smtp.gmx.de
Processed 0 CA certificate(s).
Resolving 'smtp.gmx.de'...
Connecting to '212.227.17.190:587'...
|<1>| Received record packet of unknown type 50
*** Fatal error: An unexpected TLS packet was received.
*** Handshake has failed
GnuTLS error: An unexpected TLS packet was received.


That is odd, why is thunderbird able to connect but not gnutls-cli?