efa-project.org

Hi All,

We are using E.F.A as our email gateway before our exchange 2010 server. At the moment if you send a email with a non existing email address then the E.F.A server responds with a NDR which includes the original email sent.

I believe this can be used as backscatter as someone could spoof there email address and use our server as a spam server.

How do I disable NDR or configure the E.F.A server to stop this?

Actually, the NDR is the result of a postfix REJECT or REJECT from your Exchange server. This should to the server trying to send the message, not the FROM address. Therefore, this would not be backscatter, unless the server was being spoofed, which is easily detected by the MTA (no or wrong MX/PTR record, for example).