@ratsnakegames @briankrebs @SecureOwl @chetfaliszek It should only be allowed if it has a "Reply-To" Address configured. And even then: #SMTP & #IMAP exist for quite some time!Nothing prevents the useage of the same address for different services / means. I can also use curl to send an eMail and have a ticketing system like Zammad ingest incoming eMails. #NoReply - Addresses are the equivalent of "hidden phone number" and as such belong banned for #commercial users!