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:

  tesarekjaroslav na tiscali.cz
    SMTP error from remote mail server after end of data:
    host tax.virusfree.cz [31.7.241.27]: 554 message refused (#5.7.1) - for more information visit https://www.virusfree.cz/cs/help
  jack210 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<jack210 na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  sentimentalnidivka na seznam.cz
    SMTP error from remote mail server after RCPT TO:<sentimentalnidivka na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  can155 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<can155 na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  janisek.novasek na seznam.cz
    SMTP error from remote mail server after RCPT TO:<janisek.novasek na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.