I once had the displeasure of using Fogbugz (hosted version). You could only reply to a bug if it was sent in via E-mail. Any other correspondence was to be performed via actually editing the ticket data, inline.

I called to ask if there was a way and the dude I talked to actually insinuated that I had not taken time to read the documentation. WTF?

Apparently that requirement was a "feature" -- they assumed that a bug entered manually did not require correspondence.

Yes, I was told that as well.