Re: FILTER and "unable to look up host filter.mx.example.de: No such file or directory"
- Ralf Hildebrandt:
> Jun 1 16:19:43 aias postfix/smtp: D8D3F6FCC3: to=<user@...>, relay=none, delay=0.1, delays=0.1/0/0/0, dsn=4.3.0, status=deferred (unable to look up host filter.mx.example.de: No such file or directory)it works.
> but with this:
> example.de FILTER smtp-amavis:[220.127.116.11]:10024
This confirms that the problem is with the name to address mapping.
This mapping happens in two steps:
1 - The SMTP client uses the system library's resolver routines;
these query the name server listed in /etc/resolv.conf.
2 - The SMTP client then uses the getaddrinfo() system library
routine to map MX hosts to IP addresses; this uses the "hosts"
lookup method specified in /etc/nsswitch.conf (files, nis, dns).
The above error message comes from step 2. Either nsswitch.conf
does not exist, the shared object module that implements the (files,
nis or dns) lookup method does not exist, or a file needed by that
lookup method does not exist.
It's probably easier to strace the SMTP client.