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:

  ukajitel na centrum.cz
    SMTP error from remote mail server after RCPT TO:<ukajitel na centrum.cz>:
    host cbx.virusfree.cz [5.180.49.37]: 554 5.7.1 <ukajitel na centrum.cz>:
    Recipient address rejected: Access denied, user does not exist
  justychrusty na centrum.cz
    SMTP error from remote mail server after RCPT TO:<justychrusty na centrum.cz>:
    host cbx.virusfree.cz [5.180.49.37]: 554 5.7.1 <justychrusty na centrum.cz>:
    Recipient address rejected: Access denied, user does not exist
  jiriborec na centrum.cz
    SMTP error from remote mail server after RCPT TO:<jiriborec na centrum.cz>:
    host cbx.virusfree.cz [5.180.49.37]: 554 5.7.1 <jiriborec na centrum.cz>:
    Recipient address rejected: Access denied, user does not exist