This is the mail system at host host.ru.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                  The mail system

<administrator@localhost>: Host or domain name not found. Name service error
   for name=localhost type=A: Host not found

Final-Recipient: rfc822; administrator@localhost
Original-Recipient: rfc822;administrator@localhost
Action: failed
Status: 5.4.4
Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
   for name=localhost type=A: Host not found

Add a code snippet to your website: www.paste.org