[Mimedefang] Greylisting?

[David F. Skoll]

John Rudd wrote:

> Has anyone done a grey-listing setup using mimedefang?

Yes.  Our commercial CanIt software includes greylisting.

> It seems like
> filter-sender would be the ideal place to do it.

Actually, filter_recipient, if you want to take into account the recipient
as well.  Or filter_end if you don't want to run into trouble with semi-broken
MTAs that panic if all RCPT commands are tempfailed.

> instead, I'll be using a directory, where files have filenames of
> the form sender:relay,

Be sure to sanitize the sender address.  You want to be careful not
to let an attacker create files with arbitrary names (especially names
containing ..)

> Does the implementation (with files instead of an actual database) seem
> like it will cause too many problems?

It seems a bit awkward to me.  Why not use a Berkeley DB file and the
Perl DB_File module?  Then you just tie a hash to the DB file and
(from Perl's viewpoint) everything is just a hash access.

By the way, you're posting from "john at rudd.cc" and I'm getting an SPF failure
because your posting host is b.mail.sonic.net but your SPF record reads:

rudd.cc     TXT     "v=spf1 a -all"

If you're going to publish SPF records, at least use them properly!
Your messages are getting trapped by our CanIt system because of the
SPF failures.  At some point, I will tire of releasing them...

Regards,

David.