Postmaster@mycompany.com send emails to abc@mycompany.com

[whloo]

Hi All,

Currently I am facing a problem, hopefully someone could advise how to solve the issue.

My postmaster@mycompany.com always try to send rubbish emails to example abc@mycompany.com or xyz@mycompany.com.

I catch the emails using Symantec, that marks deletion for emails send from postmaster@mycompany.com

But this way is catching the problem and delete away but is not solving the root of the problem.

How do I find the root of the problem ?

 

[58sniper]

That looks like an NDR attack. Someone is likely spoofing an address, and, when the messages can't be delivered, the NDR gets sent to your address. Do you have any filtering enabled, such as IMF, connection filtering, recipient filtering, sender filtering?

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[jimthecanadian]

If it is a NDR attack tarpitting might be a good plan too

 

[58sniper]

That's true.

SMTP tar pit feature for Microsoft Windows Server 2003

http://support.microsoft.com/kb/842851

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[whloo]

Hi all,

Thank you for the replies. Seems that the problem cannot be solved, it can only be delayed by applying Tar pit.

If I apply recipient filtering, seems that I am revealing an email is valid or invalid, then I will receive more SPAMs.

Pls advise me if you guys have solutions.

Thank you