Preventing sender address spoofing in Postfix

[cirrusadmin]

Dear All

A number of our clients are using the local email server (postfix) to send spams. One of the ways they usually adopt to hide themselves is to spoof the sender address.

is there any way to reject emails being sent from nonexistent email addresses?

Appreciate your feedback

[Denis Sirochenko]

Hello,

May be this article will help you:

The server is saturated with SPAM. There are many messages in the queue. The mail is sent slowly.
http://kb.parallels.com/en/766

Regards,
Denis.

[cirrusadmin]

Hello

Thanks but this is a totally different issue,

I would appreciate if someone could update me on this issue.