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:

  smartik na email.cz
    SMTP error from remote mail server after RCPT TO:<smartik na email.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  bos175 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<bos175 na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  alhamra22 na seznam.cz
    SMTP error from remote mail server after RCPT TO:<alhamra22 na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  nowomennocry na seznam.cz
    SMTP error from remote mail server after RCPT TO:<nowomennocry na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  zonezone na email.cz
    SMTP error from remote mail server after RCPT TO:<zonezone na email.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  tucnak.davidxd na seznam.cz
    SMTP error from remote mail server after RCPT TO:<tucnak.davidxd na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  dynastyarmor na seznam.cz
    SMTP error from remote mail server after RCPT TO:<dynastyarmor na seznam.cz>:
    host mx1.seznam.cz [77.75.78.42]: 550 5.1.1 Sorry, no mailbox here by that name.
  j.mus na centrum.cz
    SMTP error from remote mail server after RCPT TO:<j.mus na centrum.cz>:
    host cdx.spamfree.cz [94.242.232.66]: 554 5.7.1 <j.mus na centrum.cz>:
    Recipient address rejected: Access denied, user does not exist
  grimma na volny.cz
    SMTP error from remote mail server after RCPT TO:<grimma na volny.cz>:
    host ccx.spamfree.cz [195.24.76.171]: 554 5.7.1 <grimma na volny.cz>:
    Recipient address rejected: Access denied, user does not exist