Like 99% of the owners of email accounts, you may be the victim of a Spammer.

October 2006 we received reports of our domain sending multiple spam messages.  The spammer forged the From: and Reply-To: fields of his/her spam messages so it would look as if the spam email originated from our company.

As a company/web site administrator, you can't prevent spammers from forging your email address/domain in the spam that they send. You can't conceal your email addresses and only reveal them to trustworthy individuals. Your  visitors need to be able to contact you. All you can do is react when a spammer forges your name/domain on a piece of spam

First, we would like to assure you that we do not engage in the practice of spamming. It is very likely that the email in question was spam sent by someone who forged the email address/domain. If you receive an email you believe to be spam, please forward  the entire message, with the full header intact to webmaster@alliedpaperco.com. The message content and headers are essential in tracking down the individual(s) responsible for forging the email address/domain. We certainly do not want anyone sending SPAM with our name on the message.

For more information please visit:

http://spam.getnetwise.org/action/header/

or http://www.microsoft.com/mind/1299/spam/spam.asp