[Mimedefang] Off Topic: Refuse Null Sender
Jim McCullars
jim at info.uah.edu
Tue Jul 3 13:03:19 EDT 2007
On Tue, 3 Jul 2007, Jason Bertoch wrote:
> relay mail from the null sender. Blocking this will seem to eliminate some
> back-scatter as well as botnet spam. I've tried various methods with the access
> table to no avail. Any ideas?
You can easily do it in MIMEDefang:
sub filter_sender {
my ($sender, $ip, $hostname, $helo) = @_;
if ($sender eq "<>") {
return ('REJECT', "Null envelope sender not allowed")
}
return ('CONTINUE', "ok");
}
HTH...
Jim McCullars
University of Alabama in Huntsville
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