RE: Restricting Incoming Email in Exchange by From Address

I think what he may mean is that he has an Exchange box setup inside his
LAN, with an Internet-facing side as well, and that he wants to force users
inside his organisation to utilise OWA...

A better approach would be to instruct your firewall's ACL to block port
110/tcp completely..   As for OWA via VPN, why not just HTTPS?  Less hassle,
less software configuration per client-side.

(Maybe I've got it all wrong :P)

 - L. Walker

> -----Original Message-----
> From: Steve [mailto:securityfocus@delahunty.com]
> Sent: Tuesday, 21 June 2005 6:40 AM
> To: Greg Jones; security-basics@securityfocus.com
> Subject: Re: Restricting Incoming Email in Exchange by From Address
>
> Not sure I follow on the first part.  Your users can connect to your
> Exchange server via other clients like POP? If so, turn off POP/IMAP.  For
> spoofing/phishing check out using reverse DNS lookups with Exchange and/or
> SPF.  That will improve your overall email security.
>
> STEVE
> ----- Original Message -----
> From: "Greg Jones" <grjones@gmail.com>
> To: <security-basics@securityfocus.com>
> Sent: Saturday, June 18, 2005 12:30 PM
> Subject: Restricting Incoming Email in Exchange by From Address
>
>
> In Exchange (any version), I would like to disallow email coming from
> the Internet (smtp) that has a From address of my domain.  This would
> force our employees to use OWA or Exchange (via VPN of course).  This
> would help with phishing and worms that are fooling some of our
> employees (e.g., emails from admin@mydomain.com).  Is this possible?
>
>  Greg