Due to a change at Yahoo's end this past weekend, most major email providers will now filter as spam or outright reject any email message coming "From: [anything]@yahoo.com" which wasn't originally sent through Yahoo's own mail servers.
Thus, if you have entered a Display Email address @yahoo.com in your E-junkie Profile, we are now having to send your thank-you emails as "From: email@example.com", in order to help ensure your thank-you emails can get delivered at all. We are also providing a "Reply-to:" header for any Display Email @yahoo.com, so buyers should still have no problem simply replying to their thank-you emails to contact you. To help buyers identify these thank-you emails as legitimate, we're considering alternative usernames we might put in front of our @ sign rather than using firstname.lastname@example.org, such as using email@example.com; we'd be glad to consider other suggestions.
One easy way around all this would be to change the Display Email in your E-junkie Profile to anything not @yahoo.com, though the new Display Email you choose should still be one that delivers to you. Ideally, this should be something @ your domain name if you have your own Web site, but other non-Yahoo webmail addresses @gmail.com, @hotmail.com, etc. should work fine as well.