note 92527 added to function.mail

Problem: mail disappearing; not being sent There are many reasons why your mail might fail to be sent, but one particularly obscure reason is as follows. You must take extra care if the machine that is sending the mail also operates mail forwarding for your domain and you are sending mail to a user at that domain. In this situation, it is common for the MTA to avoid doing a "proper" MX look-up because it "knows" that there is a local list of mail-forwarding rules. This saves resources, and normally shouldnt be a problem, of course. HOWEVER, if you deliberately alter your MX record to point to a mail server hosted elsewhere and, e.g. update your mail forwarding rules at that location, AND the server that sends your PHP-generated mail "decides" that it will save resources by not checking the MX record THEN it will use your old set of forwarding rules because it is ignoring your MX record. If an appropriate forwarding rule does not exist locally, then the mail may be dropped without generating any error (i.e. no "bounce" message). The symptom of the problem is that mail to certain users at your domain will be wrongly delivered or not delivered at all. An obscure problem, perhaps, but one that I have experienced, and which took a long time to solve! ---- Server IP: 87.124.35.190 Probable Submitter: 83.104.168.235 ---- Manual Page -- http://www.php.net/manual/en/function.mail.php Edit -- https://master.php.net/note/edit/92527 Del: integrated -- https://master.php.net/note/delete/92527/integrated Del: useless -- https://master.php.net/note/delete/92527/useless Del: bad code -- https://master.php.net/note/delete/92527/bad+code Del: spam -- https://master.php.net/note/delete/92527/spam Del: non-english -- https://master.php.net/note/delete/92527/non-english Del: in docs -- https://master.php.net/note/delete/92527/in+docs Del: other reasons-- https://master.php.net/note/delete/92527 Reject -- https://master.php.net/note/reject/92527 Search -- https://master.php.net/manage/user-notes.php