Subject: Eric Sunshine mail delivery failure

From: René Scharfe <[email-masked]>
Date: Sun, 23 Aug 2015 11:35:52 +0200

Eric, hope you see this reply on the list. Direct replies to 
[email-masked] are rejected by my mail provider on submit in 
Thunderbird with the following message:

     Requested action not taken: mailbox unavailable
     invalid DNS MX or A/AAAA resource record.

And with this one when using their web interface:

     A message that you sent could not be delivered to one or more of
     its recipients. This is a permanent error. The following address
     failed:

     "[email-masked]":
     no valid MX hosts found

It seems web.de wants you to get an AAAA record before I'm allowed to 
send mails to you.  Sounds crazy.  Sorry about that.  Time to find a
better provider, I guess. :-(

René