Re: [exim] identifying real hotmail servers

Jeff Lasman wrote:

> We'd like to whitelist real hotmail servers. We've found we can't
> identify them from their spf records; they don't keep those up-to-date
> <frown>.
>
> Currently hotmail appears to be using only servers matching this:
>
> bay0-omcX-sYY.bay0.hotmail.com
>
> where "X" is a single digit and YY is either one or two digits.
>
> Is there a way to easily check for this in an lsearch (or perhaps some
> other kind of search) through a whitelist file?
>
> Or some other easy way to do it?
>
> Or some other method completely different, that doesn't rely on their
> published spf records?
>
> Any help would be appreciated.
>
> Thanks for your consideration.

$sender_host_name contains the rdns of the connecting host *IF* the A
record of that rdns points back to the same IP. I identify connecting
hotmail servers like this:

condition = ${if match_domain{$sender_host_name}{*.hotmail.com}}

If you wanted to be more strict, taking what you said above regards 'X'
and 'Y' (untested):

condition = ${if
match{$sender_host_name}{\N^bay0-omc\d-s\d\d?\.bay0\.hotmail\.com$\N}}

Hope that helps,

Mike