Mail System Error - Returned Mail

This Message was undeliverable due to the following reason:

Each of the following recipients was rejected by a remote mail server.
The reasons given by the server are included to help you determine why
each recipient was rejected.

    Recipient: <femme_at_fastclick.net>
    Reason: <femme_at_fastclick.net>: Relay access denied

Please reply to <Postmaster_at_mx.bigpond.com>
if you feel this message to be in error.

The following attachments have been removed from the bounce message: letter.zip

attached mail follows:

Dear user of fastclick.net,

We have found that your e-mail account was used to send a large amount of junk email during the recent week.
Most likely your computer had been infected by a recent virus and now contains a trojaned proxy server.

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

Best regards,
The fastclick.net team.