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:

  klacik.s na seznam.cz
    SMTP error from remote mail server after RCPT TO:<klacik.s na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  justin.bitch na seznam.cz
    SMTP error from remote mail server after RCPT TO:<justin.bitch na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  ediknovak na email.cz
    SMTP error from remote mail server after RCPT TO:<ediknovak na email.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  freestyle13 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<freestyle13 na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  vasil1982 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<vasil1982 na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  nicky1222 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<nicky1222 na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  dvori15 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<dvori15 na seznam.cz>:
    host mx1.seznam.cz [77.75.76.42]: 550 5.1.1 Sorry, no mailbox here by that name.