 smtp; 550 5.1.1 <zusvid@jes.cz>: Recipient address rejected:
    undeliverable address: host newmail.jes.cz[31.132.31.143] said: 550 5.1.1
    <zusvid@jes.cz>: Recipient address rejected: User unknown in virtual
    mailbox table (in reply to RCPT TO command)
