EDIT: I recieved a call back from the corporate office of the retailer. It was them that emailed me but it was from a different department than customer service, which was why customer service thought it could possibly be a phishing scam. Mods, feel free to delete and I apologize for wasting anyones time. A word of warning, I posted that I was buying an item from a certain store in the Merch Beyond thread and one thread in the general forums, (the only place online I've said I was buying that item / where I was buying that item outside of my actual purchase) and may have received a phishing attempt via email because of that post. Since I reached out to the store by phone after receiving the email I did not experience any lose from it (and the store itself is so behind the times it can't tell if it was them who emailed me or not for another few days as it takes that long for emails to attach to customer profiles) but I thought I should pass the warning on to anyone else who may have posted about planned purchases in this forum.
I'm not sure how anyone would have obtained your email address solely from what you've posted on the forum about buying a particular item, but web spiders are getting more sophisticated and able to make connections between what are otherwise unassociated accounts. I'll send a report on your post anyway, just so that the site and tech admins are aware of it, but you may also want to say something about this in a QS&F thread (directing it to @AntonyF should draw his attention, in case of a possible tech solution from our end.)
I don't blame trekbbs at all, you guys can't control the people visiting the site. And the retailer can't confirm if it was them or not yet (this is a major retailer) but if it is one than it was either this site they got the details of my purchase or the retailer has been hacked and doesn't know it, so I thought I should alert others here just in case I will do as you suggest.