Re: [swinog] reject_unknown_client_hostname

Martin Blapp wrote:

Hi,

...

Does anybody know whether the Postfix checks reject_unknown_client_hostname [aka Reject the request when 1) the client IP address->name mapping fails, 2) the name->address mapping fails, or 3) the name->address mapping does not match the client IP address] follows actually any requirement by a RFC? If so, which one?

To reject any mails with errors 5XX with just ONE criterium is very bad behaviour anyway and will always lead to false positives.

hmm, how about "unknown user" :-)

Anyway, the default postfix reject for the above is a 450 and always 450 if the failure was caused by a lookup problem.