Stopping sendmail from allowing external hosts to use local email addresses

[Alex Neuman]

SPF - spf.pobox.com

-----Original Message-----
From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK] On Behalf
Of Gary Alexander
Sent: Friday, August 13, 2004 2:12 AM
To: MAILSCANNER at JISCMAIL.AC.UK
Subject: OT: Stopping sendmail from allowing external hosts to use local
email addresses

Hi All

As per my subject, can anyone point me to some documentation on how to
achieve this in sendmail ie: If a most likely virus infected host tries
to send a mail using someuser at mydomain.co.za to
someotheruser at mydomain.co.za and that host is not one of a set of
predefined hosts, is there a way to reject it?

This would really help to cut down the load of viruses I've seen lately
that are doing this, and I have no valid users that would require to do
this.

Thanks for any help in this regard.

Gary Alexander
Technical Manager
Sahara Systems, South Africa
Tel: +27 (0)11 5421000
Fax: +27 (0)11 5421100





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