Hallo,

meine Mails an t-online Kunden werden plötzlich blockiert.

This message was created automatically by mail delivery software.

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

xyz@t-online.de
all hosts for 't-online.de' have been failing for a long time (and retry time not reached)

Reporting-MTA: dns; mout39.gn-server.de

Action: failed
Final-Recipient: rfc822;xyz@t-online.de
Status: 5.0.0

MfG

Uli Reiter