Re: [ILUG-BOM] a question on open relay??

On Mon, 2004-11-01 at 12:24, Clifford D'Mello wrote:

...

Best remedy is to enable smtp authentication on the server

This will not solve the problem because an MX cannot ask other servers to authenticate. It has to accept mails for the domain.

Not really. Authentication is primarily used for MAIL from: user@domain command. AUTH is never used for RCPT to: command.

So when any other client/server sends mails to your MX host and has MAIL from: domain(s) of local host, it will reject mail saying relaying denied.

If the client/server AUTHenticates itself by initiating AUTH and giving correct Authentication info, will enable local domain(s) in MAIL from:

Remember, AUTH is optional and should happen before MAIL from: command.

-- Clifford

HTH With regards,