For some reason the setting to wraps lines of text is really hidden away–
Edit > Preferences > Advanced > General > Config Editor
–then search for 'wrap'.
Thunderbird's great and all, but it's also messy!
Runs, but no window
A couple of times I've gotten stuck in situations where it would start, but no windows would actually appear, and it would just keep hogging CPU in the background.
thunderbird -safe-mode has always worked to fix things for me. Once you're back in Thunderbird you can try re-enabling add-ons to help determine the problem. For me it's always bloody Lightning.
Other things you might like to try are deleting everything in
~/.cache/thunderbird, and making sure the
.parentlock is deleted when TB quits.