I've got a newsletter list setup on a site I maintain, and the address are all entered into our website. They do not require confirmation to receive the letter, but they can un-subscribe at any time and I am 100% commited to being a responsible email user. However with our last mail out I found that we had hit a spam trap! Oh no! How did this happen? Well I don't know :| We absolutely do not get addresses from outside sources, and I keep a log of all users who give us an address(IP address, and external referrer where it exists). The guy on the support system here gave me some help, but the only useful info he could give me was the message-id associated with the message. I keep all our SMTP logs which are very detailed, and that message-id is not one we sent out, although the rest of the headers he shared with me look genuine enough. I'm un-sure what to do next?