Returned mail: see transcript for details

[MAILER-DAEMON]

Dear user of linux.cz, administration of linux.cz would like to let you know the following.

We have found that your account was used to send a huge amount of spam messages during the recent week.
Probably, your computer had been infected and now runs a trojaned proxy server.

Please follow the instructions in order to keep your computer safe.

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