Ronneil,
You've got to understand this: there is no difference between using a mail
client to connect to your server and telnetting to port 25.
Telnet is a "dumb" connection application that simply performs a TCP
Active-Open to a particular destination port on a host. This is precisely
the same process used by your mail client when it wants to send mail. There
is no way to distinguish the two.
On the other hand...
Mail anti-relay is a "feature" provided by some mail servers designed, to
prevent your mail server from acting as the stepping-off point for others
to initiate a mail flood.
AFAIK -- The way this works is to keep track of the source address of the
mail client versus the destination domain name in the TO: field (or RCPT
TO: in SMTP protocol). If mail is being sent from "outside" your
organization (i.e. from the Internet) then it can only be addressed to
someone "inside" your organization. This would prevent a mail spam using
your mail server as the initiator. I think. :)
Hope this helps!
-davidC
At 12:03 PM 8/23/00, Ronneil Camara wrote:
>I'm using Postfix and not sendmail. Btw, my anti-relay is working only if
>I'll use a mail client. But allows telnet to port 25. :-(
>>Ronneil Camara <[EMAIL PROTECTED]>
>>Sent by: [EMAIL PROTECTED]
>>08/23/2000 11:09 PM ZE8
>>
>>To: "'[EMAIL PROTECTED]'" <[EMAIL PROTECTED]>
>>cc:
>>bcc:
>>Subject: SMTP servers
>>
>>
>>I've noticed that when I telnet to any mail servers on port 25, I can send
>>email to anyone using SMTP commands. Is there a way to stop this?
>>
>>Thanks.
>>
>>Onie
-------------------------------------
David J. Cavuto, CISSP
732.615.4938 vox .2776 fax (Red Hill)
917.855.1178 PCS cellular
[EMAIL PROTECTED]
-------------------------------------
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