Correo rechazado por error 552 5.2.0

Buenos días:

A mí me pasa algo parecido. Que yo sepa, una persona no puede enviarme correos porque siempre se los rechaza con un mensaje del tipo:

Sent: Saturday, July 27, 2013 11:38 PM
Subject: Delivery Status Notification (Failure)


Delivery to the following recipient failed permanently:

     xxxxxxxxxx@telefonica.net

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for
the recipient domain telefonica.net by tnetmx.telefonica.net.
[213.4.149.227].

The error that the other server returned was:
552 5.2.0 5Zea1m0053l2eVd07ZeblW internal error

----- Original message -----

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;