mozilla-thunderbird 0.7.3-r1 gives an XUL error displayed in the png used as a reference URL here when you try to send an HTML message and it wants to warn you that maybe you don't really want to be sending HTML email. Reproducible: Always Steps to Reproduce: 1. Compose an HTML email that would cause Thunderbird to ask you if you want to send an HTML email. 2. Hit send 3. Receive the png listed above. Actual Results: Got the png listed above. Expected Results: should have asked me if I wanted to send an HTML message.
this is from a couple releases ago...