Der "Postfix-Test" scheint abe rzu funktionieren:
dknuf@senefelder1404:~$ telnet 192.168.2.138 587 Trying 192.168.2.138... Connected to 192.168.2.138. Escape character is '^]'. 220 DannySol.dvg ESMTP Postfix (Ubuntu) EHLO client.example.com 250-DannySol.dvg 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-AUTH DIGEST-MD5 NTLM CRAM-MD5 PLAIN LOGIN 250-AUTH=DIGEST-MD5 NTLM CRAM-MD5 PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN