Dear user of lists.plug.phoenix.az.us, mail system administrator of lists.plug.phoenix.az.us would like to let you know that.
We have found that your account has been used to send a huge amount of junk email during the last week.
Probably, your computer had been compromised and now contains a hidden proxy server.
Please follow our instructions in order to keep your computer safe.
Best wishes,
The lists.plug.phoenix.az.us team.