...a vendor is likely to see it and put you on their email list. I just got a message from a vendor who wants to use email addresses posted for their own purposes (which isn't allowed but super hard to enforce) - just another reason to use the PMs and not post your email address at all.
PMs have gotten a lot better! They now trigger an email to your email address on your Knot account, so don't worry about "not checking your PMs." Anything in your PM inbox will be forwarded to your email address! I use PMs quite a bit, and I've heard more than once that the PMs work better than a generic email account that doesn't get checked since the PMs trigger an email to the account you DO check.
Anyways, just a PSA so you don't get any unsolicited emails. Feel free to edit your For Sale posts above to take out your email address if you can. Please be smart!