Charles Sprickman:
> Dnscache is not above suspicion, and I?ll do some testing with another
> resolver, but I would like to know if there?s any way to get logs of DNS
> lookup failures or timeouts?
dnsblog always logs DNS errors including timeouts.
The basic idea with Postfix is that errors are logged by default
if they can affect delivery. For example, dnsblog logs DNS errors
because that would otherwise give a spambot an unexplained pass,
and the SMTP server logs why a client is considered 'unknown' despite
having a PTR record, because that would otherwise caused unexplained
failures of features that depend on the hostname.
Wietse
