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Legacy Forums => Experienced User Forum => Topic started by: mardek01 on August 29, 2004, 08:50:26 PM

Title: Unwanted mail relay behind NAT
Post by: mardek01 on August 29, 2004, 08:50:26 PM

Hi,

Iam running my SME 6.04 server behind a NAT. Via portforwarding on my NAT router I get my mail delivered on my SME.

In case someone tries to use my mail server as a mail-relay, does the the SMTP server see the (local) IP adress from my router as the sender or not? In case it does I think it is possible for an abbuser to actually use my mailserver as a relay.

As I am trying to understand what actually happens in a SME server, all info on this aspect is  appreciated.    

Regards,
Mardek

Title: Unwanted mail relay behind NAT
Post by: Boris on August 30, 2004, 08:37:15 AM

SME see the real (Internet) address of the SMTP server who trying to send, not your portforwarding router's and if its not in the list on local addresses denies SMTP relaying.

Title: Unwanted mail relay behind NAT
Post by: arne on August 30, 2004, 11:43:25 PM

I Agree with Boris.

I am also now using a SME 6.0.1 behind a NAT router so the SME got only a local IP. Have also carried out some checks to se if it were relying. Have not discovered any problems.

(Returned back to SME after some months of dayly reconfiguration of Fedora Core 2  :hammer: )

Here is a tool you can use for checking if it's relaying:

http://msv.dk/ms009.asp