I've gone through the following articles doing the steps to ensure that thunderbird will open links in Chromium instead of Firefox:
Everywhere else in KDE, things open appropriately in the right browser (chromium). I've tried clobbering my profile, and starting again from scratch.
I'm at a loss here, I can't figure out why everything else is using chromium as the default browser, but thunderbird continues to use firefox, no matter what.
I'm running ArchLinux, in KDE, and I've set up chromium as the default browser.