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:

  apepo1 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<apepo1 na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  seris na seznam.cz
    SMTP error from remote mail server after RCPT TO:<seris na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  loopen na seznam.cz
    SMTP error from remote mail server after RCPT TO:<loopen na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  teckanovak na seznam.cz
    SMTP error from remote mail server after RCPT TO:<teckanovak na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  sexy.boy na seznam.cz
    SMTP error from remote mail server after RCPT TO:<sexy.boy na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  saky125 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<saky125 na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.
  kamil.mali na seznam.cz
    SMTP error from remote mail server after RCPT TO:<kamil.mali na seznam.cz>:
    host mx2.seznam.cz [77.75.76.32]: 550 5.1.1 Sorry, no mailbox here by that name.