I like thunderbird. It’s a free email client and lets me read all of my accounts at once. I hate that it defaults to edge browser though.
There is no easy to find option for changing the default link handler in thunderbird. To fix this you need to edit your config profile.
Click the hamburger in the upper right, options, options.
Next click on the general tab and then config editor.
After dismissing the warning, search for the following settings:
Double click them to make the “true” for http and https.
Click ok to save and then use your links again. It will prompt for which browser this time. Browse to find it and select it. From now on it will use that browser instead of Edge.