My new provider offers on port 587 "250-AUTH GSSAPI NTLM" I am trying to configure my postfix using as relayhost this smtp server. Using kmail I am able to simply provide the username, an email address, and a password. However I have a script that has to send an email. I use mailx to do that, which sends the message to postfix and postfix should send it to the server of my provider. My previous provider offered LOGIN an PLAIN, for which it apparently was easy to configure Postfix. I configured both NTLM and GSSAPI as mechanisms in Postfix. In /etc/postfix/ sasl_passwd the username and password are configured. Error messages in /var/log/mail: postfix/smtp[14307]: warning: SASL authentication failure: GSSAPI Error: No credentials were supplied, or the credentials were unavailable or inaccessible (No Kerberos credentials available (default cache: KEYRING:persistent:51)) postfix/smtp[14307]: 92C8D101152: to=<xxxxx@yyyyy.nl>, relay=smtp.yyyyy.nl[212.113.64.zz]:587, delay=16453, delays=16453/0.02/0.14/0, dsn=4.7.0, status=deferred (SASL authentication failed; cannot authenticate to server smtp.delta.nl[212.113.64.82]: generic failure) -- fr.gr. member openSUSE Freek de Kruijf