I'm sorry, there is no discrepancy between 1.5i and 1.5j. Both of them have the same statement: If domain ^= '' Then Return 0 Whether or not an ACK=YES field is propagated is irrelevant. By the way it only means the same thing as having ACK=YES on the local list. The point is that routine SENDLIST does: Parse var fromid '@' '.'domain and then you have the IF I quoted above. If it doesn't work, there are two explanations: 1) DOMAIN gets disrupted somewhere. It's used before (in the mail parsing routine) and after, but only in PROCEDUREs. 2) FROMID is incorrect. I'd say the problem is here, but can't see why... Eric