How To: Change Default Mail Client on OSX
When I moved away from Entourage to Thunderbird I had a huge issue with mailto: html links still attempting to open Entourage to send emails. OS X itself simply does not provide a simple way to change this default behavior.
So, the trick is to open OS X’s Mail Client and use that. Simply create a dummy account, it doesn’t matter what info you put in as you won’t be using it. Once Mail is opened, go to Preferences then click on the General Tab. There will be a “Default Mail Reader” drop down menu. Choose your default client (even Firefox or Safari if you have something like Zimbra or another web mail) and exit the client.
The other, and possibly better trick if you’re going to make this change across multiple computers such as an entire Enterprise setup is to edit one of the plist files.
In ~/Library/Preferences/ look for com.apple.LaunchServices.plist
LSHandlerRoleAll com.mail.client LSHandlerURLScheme mailto
Options for mail client would be com.mozilla.firefox or com.microsoft.entourage or the preferences name of any other mail client. These can easily be found in the same folder. Once this is done, mailto: links will then open in your preferential mail client!