Debian Testing/Wheezy, kernel 2.6.38, Postfix I've had a procmail receipe in place for a few weeks now and it's been working well. :0 * ^(TO|FROM):.+@mydomainname.* { :0c # Send a copy to the other email account. ! someone@anotherdomainname.com # File the original as normal :0 foldername } Then a few days ago, probably after some OS updates, it fails with: status=deferred (host mail.*******.*****.com[000.00.00.0] said: 451 4.4.0 DNS temporary failure (chkuser) (in reply to MAIL FROM command)) (I've removed the data identifying the destination) I have also tried sending an email directly using /usr/bin/sendmail and that produces the same result, whatever the emails destination, so I'm assuming it must be my setup. I can't explain why it worked before but doesn't now though. I have really no idea what this means as Postfix configuration is a series of magical incantaitions which I don't understand. Some help would be much appreciated. -- Barry Samuels