Mail delivery failed: returning message to sender

[Mail Delivery System]

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:

  ddd na ddd.cz
    SMTP error from remote mail server after end of data:
    host ign-mx1.webglobe.com [217.67.31.4]: 550 Message discarded as high-probability spam