The email integration service has again been updated. This time I added HTML posting capability. No longer will your HTML emails be converted to ugly text format. Also, the threading was broken (how'd I miss that last May??).
The HTML posting is fragile and doubtless will break on some of the horrible HTML generated by some emailers. I did test with my Thunderbird, as well as Yahoo Mail and GMail. If you post via HTML and find that the message came out ugly etc. let me know and I'll attempt to add fixup code for your mailer.
[edit] I just discovered that quotes are not appearing in emails sent out from the forum system. Quotes in incoming HTML email are being properly turned into quotes in the posted forum messages, it's just that the resulting outgoing email notifications don't contain those quotes. I'll work on it as soon as I can...