Jakub Wasielewski wrote: > The addresses are: > valid recipient: proboszcz at parafia-sw-stefana.pl > nonexistent recipient: proboszczd at parafia-sw-stefana.pl I can't see anything wrong with your filter, and the server petrus.opoka.org.pl does indeed reject invalid recipients at RCPT time. So... I'm at a loss... sorry! Regards, David.