Mozilla Firefox and Thunderbird as default browser and mail client I use Firefox and Thunderbird for browsing and email. In the Safari Preferences, Firefox is set to be default browser. Each time I start Firefox, it asks if I want it to be the default browser. Same thing with Thunderbird. If I disable this check in Thunderbird, and click a mailto-link on a webpage, Apple Mail opens. 

How can I set Firefox and Thunderbird to be the default clients, without having to confirm this each time I restart my computer?
You had 2 questions.

1- Go to your Firefox preferences and uncheck the Always check for default browser.



2- For Thunderbird do this:


  Set Thunderbird as the operating system default

Launch the default Mac OS X email application (called "Mail", located in the /Applications folder.)
Select Mail | Preferences from the menu.
On the General tab, select "Thunderbird" from the Default email reader drop-down list.
Close Mail.