Since I switched ISP I'm having quite some problems with my mail. Sometimes mails will be rejected by the receiving side with the following message:
This is the mail system at host mail.xyz.ch.
I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can delete your own text from the attached returned message.
The mail system ...
Action: failed Status: 5.7.1 Remote-MTA: dns; postrelay2.lrz-muenchen.de Diagnostic-Code: smtp; 550 5.7.1 Client host rejected: cannot find your hostname, [213.xxx.yyy.zzz]]
So apparently the receiving side of the communication is complaining that it could not find the hostname mail.xyz.ch in the reverse DNS lookup.
Now I'm sure that I configured all the PTR entries in bind to point to the real hostnames:
; ; BIND reverse data file for broadcast zone ; $TTL 604800 @ IN SOA dns3.xyz.ch. root.xyz.ch. ( 20100328 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; NS dns3.xyz.ch. NS dns2.xyz.ch. 129 PTR ssh.xyz.ch. 129 PTR www.xyz.ch. 129 PTR mail.xyz.ch.
But a reverse DNS lookup still only provides the the ISP name:
Any idea on how to fix this? Do I have to contact my ISP?