Subject: Re: How can you block empty email address at sendmail?
To: John Maier <email@example.com>
From: Jeremy C. Reed <firstname.lastname@example.org>
Date: 01/08/2001 10:10:28
On Mon, 8 Jan 2001, John Maier wrote:
> MAIL FROM:<>
> and the sendmail thinks the mail is from postmaster.
> So how do I create a rule to tell sendmail to disallow blank 'from' emails?
You probably don't want to reject mail because of a null or blank envelope
RFC 1123 says an "empty reverse path MUST be supported" and:
If there is a delivery failure after acceptance of a message,
the receiver-SMTP MUST formulate and mail a notification
message. This notification MUST be sent using a null ("<>")
reverse path in the envelope ...
Maybe you can use some other rules or ideas to block these spammers.
Jeremy C. Reed