I have also experienced the same "symptoms" after updating mozilla-thunderbird last night to version 1.5-0ubuntu3. Apparently, Enigmail was also removed and there's no corresponding package for it yet.
Steps to reproduce the "symptoms":
1 - In Thunderbird, go to Views --> Headers --> All
to "fix" it:
1 - In Thunderbird, go to Views --> Headers --> Normal
I have also experienced the same "symptoms" after updating mozilla-thunderbird last night to version 1.5-0ubuntu3. Apparently, Enigmail was also removed and there's no corresponding package for it yet.
Steps to reproduce the "symptoms":
1 - In Thunderbird, go to Views --> Headers --> All
to "fix" it:
1 - In Thunderbird, go to Views --> Headers --> Normal