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:

  smarkus1 na volny.cz
    SMTP error from remote mail server after RCPT TO:<smarkus1 na volny.cz>:
    host cbx.virusfree.cz [5.180.49.37]: 554 5.7.1 <smarkus1 na volny.cz>:
    Recipient address rejected: Access denied, user does not exist
  straka.danik na seznam.cz
    SMTP error from remote mail server after RCPT TO:<straka.danik na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  krotofl na seznam.cz
    SMTP error from remote mail server after RCPT TO:<krotofl na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  czechsneck na seznam.cz
    SMTP error from remote mail server after RCPT TO:<czechsneck na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  cara895 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<cara895 na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  pepa.kiss.me na seznam.cz
    SMTP error from remote mail server after RCPT TO:<pepa.kiss.me na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.