Subject: How can you block empty email address at sendmail?
To: None <>
From: John Maier <>
List: netbsd-users
Date: 01/08/2001 11:35:21
I have been locking down my email and I seem to have one last spam hole.
The spammers send:

and the sendmail thinks the mail is from postmaster.

So how do I create a rule to tell sendmail to disallow blank 'from' emails?

I thought I saw an option at to disallow blank email
address, but I can't find it now.