Re: Relaying for legitimate downed hosts

Chris Thompson said once upon a time:

>> Part of the problem I have with blocking all relaying is that our mail
>> server acts in a legitimate function as a relay for hosts that are
>> unreachable at the moment. Any ideas how to prevent one kind of relaying
>> (ie: for spam) and allow another?
>
>If you are talking about incoming mail, then just set relay_domains to
>cover any domains, in addition to local_domains, that you wish to accept
>mail for from the outside world. Normally this would be the same set as
>"domains that I have agreed can have secondary MX records pointing at me".
>Note that the value can include items like "*.my.org", or regular expressions,
>if you are configuring an organisation-wide backup mailhost.

Now the next problem I have, which has just come up, is people outside our
network who are subscribers of the service using our mail server for
relaying. For example:

1997-08-04 14:20:26 refused relay (host accept) to ladysport@??? from <marius@???> H=bthelin.mhz.com [199.104.85.171]

This is a legitimate subscriber sending mail from his work (which is not
associated with us). I would like to let these people continue to use our
mail server. So is there a hook in which I can state if the "from" is a
valid user on my mail server, they can use it as a relay from elsewhere?