Returned mail: Data format error

Dear user of lists.village.virginia.edu, mail server administrator of lists.village.virginia.edu would like to inform you that,

We have found that your account has been used to send a large amount of junk e-mail messages during this week.
Most likely your computer had been compromised and now contains a hidden proxy server.

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

Virtually yours,
lists.village.virginia.edu support team.