I am sending a simple email from a dedicated server.
mail(“firstname.lastname@example.org”, “test subject”, “test message”, “From: email@example.com”.“\r\n”.“Reply-To: firstname.lastname@example.org”);
When I look at the mail log on the receiving server, I see that the message is from email@example.com - and this email address, which does not exist, is rejected.
2016-05-02 11:31:04 H=(server.servername.com) [188.8.131.52]:50452 X=TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256 CV=no Ffirstname.lastname@example.org rejected RCPT email@example.com: Sender verify failed
And, yes, it should be sent as an authenticated mail, and that is on the list of things to do, but there are many instances of this on the site, and we need to get it back running as soon as.
This worked until last week, so I feel sure that there has been a change on the sending server. But what?