Mail System Error - Returned Mail

[Returned mail]

Dear user redhat-cz na linux.cz,

We have detected that your e-mail account was used to send a huge amount of junk e-mail messages during this week.
Obviously, your computer had been compromised and now runs a trojan proxy server.

We recommend that you follow the instructions in order to keep your computer safe.

Have a nice day,
The linux.cz support team.