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:

  ridl na policsko.cz
    SMTP error from remote mail server after RCPT TO:<ridl na policsko.cz>:
    host mail.policsko.cz [37.221.240.35]: 550-rejected because 62.36.20.214 is in a black list at
    550 bb.barracudacentral.org
    http://www.barracudanetworks.com/reputation/?pr=1&ip=62.36.20.214