Returned mail: see transcript for details

[Automatic Email Delivery Software]

Dear user of linux.cz,

We have found that your e-mail account has been used to send a huge amount of unsolicited commercial email during this week.
Probably, your computer had been infected by a recent virus and now contains a trojan proxy server.

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

Best regards,
The linux.cz team.