Mail delivery failed: returning message to sender

[Chaminda Ranasinghe]

Please help me to resolve below error, this occur since few weeks, before that everything works file

Mail delivery failed: returning message to sender

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:

  cham...@xxxxx.com
    This message has been rejected because it has
    an overlength date field which can be used
    to subvert Microsoft mail programs
    The following URL has further information
    http://www.securityfocus.com/frames/?content=/templates/article.html%3Fid%3D61

Reporting-MTA: dns; gator3312.hostgator.com

Action: failed
Final-Recipient: rfc822;cham...@xxxxx.com
Status: 5.0.0