Hi. I have just read elsewhere on this forum that leaving Plesk in the default 127.0.0.0/8 setting in Server Wide Mail Prefernces, is in effect leaving the server open relay. I changed it to 127.0.0.1/32 as per the advice I read, but then I questioned whether it should be 127.0.0.0/32 or 127.0.0.1/32. Was I right to follow this advice and which localhost IP should it be? .1 or .0 Many thanks!