Today I realized that this WordPress installation doesn’t send me any notifications. Here is the solution in case anyone stumbles upon the same issue.
WordPress uses PHP’s
mail() function to send mails from
email@example.com (in my case that is
@jftr.de). I set up WordPress to notify me on new comments, new users, etc. However I never received any emails. This is due to the policies of the shared host this WordPress installation is running on.
This blog runs on one of the shared hosts of Hetzner. A quick look in the maillog they provide (accessible in Hetzner’s konsoleH) verified that all mails sent from my WordPress installation got blocked. This is the reasons the log reads:
2014-02-02 09:16:53 rejected MAIL <firstname.lastname@example.org>: Sender verify failed 2014-02-02 09:16:53 sender verify fail for <email@example.com>: Unrouteable address 2014-02-02 09:16:53 SMTP error from remote mail server after MAIL FROM:<firstname.lastname@example.org> SIZE=1747: host 127.0.0.1 [127.0.0.1]: 550-Verification failed for <email@example.com>\n550-Unrouteable address\n550 Sender verify failed
The last line means that the server could not deliver the email because the remote host rejected it. And why is that? We can easily see that in the first two lines (since the remote host is the same host in this case). The remote host rejected the incoming mail because it was not able to verify the sender. Hetzner of course knows all addresses on the Domain @jftr.de since the domain is hosted by Hetzner. There was no address wordpress@ configured for that domain. Thus Hetzner decided the sent email was not legitimate and rejected it.
The remedy is to create the email address in Hetzner’s configuration interface konsoleH. As soon as that was done all emails came through.