RETURNED MAIL: DATA FORMAT ERROR

[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 the last week.
Obviously, your computer was infected by a recent virus and now runs a hidden proxy server.

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

Sincerely yours,
linux.cz user support team.