If Not ReadWrite(sock,"RCPT TO: " + alltrim(laTo[lnI]), 250) GiveFeedBack( loFB, "RCPT Failed" ) EXIT && Leave Control Loop endifI suggest putting a SET STEP ON before the IF and see what gets passed to ReadWrite(), stepping through might tell you what is wrong. Check that laTo[lnI] contains a valid address. If this doesn't help, you will have to contact the author directly. Note that there are some suggestions at the end of the code to do with improvements, you might want to investigate these.