One of the best extensions ever Rated 5 out of 5 stars
The great thing about Stylish is that it can do nearly anything in Mozilla-based apps.
For example, I've just started using Postbox. Postbox tries to scale images to the window size, but it's very slow to do this and pretty bad at it - working only when it feels like it. The fix? Disable the built-in auto-fit and add a Stylish script to do the job. Perfect results. I did this back in Thunderbird 2 and have carried the script over
max-width: 100% !important;
by someone very helpful on Mozillazine
Someone earlier said they were using Stylish to colour topics in Postbox. I used to do this in Thunderbird, but it's not working in Postbox. If anyone has the script please paste it and find me on Mozillazine :-)
Oh, the old interface (0.56) was much better.