I run a custom webshop where my system sends out different notifications. Unfortunately yesterday I started receiving a lot of rejected emails. It's not all emails being rejected, only a specific kind.
In the example below I've received a response from Google, but I have the same problem with other mail servers.
What can be wrong? I've searched all over, and I'm clueless.. (PS: Masked some server info)
From: MAILER-DAEMON@******.server.com (Mail Delivery System) Date: 23. jun 2011 14.57.18 CEST To: me@********.com Subject: Undelivered Mail Returned to Sender This is the mail system at host ******.server.com. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <****.****@gmail.com>: host gmail-smtp-in.l.google.com[18.104.22.168] said: 550 Action not taken (in reply to end of DATA command) Reporting-MTA: dns; ******.server.com X-Postfix-Queue-ID: 573DF7E0F1 X-Postfix-Sender: rfc822; me@******.com Arrival-Date: Thu, 23 Jun 2011 14:57:17 +0200 (CEST) Final-Recipient: rfc822; ****.****@gmail.com Action: failed Status: 5.0.0 Remote-MTA: dns; gmail-smtp-in.l.google.com Diagnostic-Code: smtp; 550 Action not taken From: Website.com <sales@****.dk> Date: 23. jun 2011 14.57.17 CEST To: ****.****@gmail.com Subject: Amount refunded to your account - 40700 ... HTML content here ....