Cannot Set Default Mail App in El Capitan

holy sh*t monkey. yes, don't use the dropdown as it doesn't work. just like the fact that nobody at Apple apparently works on the mail app.

Thanks @JRMH-Perth - this totally worked for me.

Thank you!

Tip: As another user suggested try restarting your computer immediately after you set the default mail client!

This worked for me and I was able to successfully set Outlook 2016 as my default mail client.

Thank you Linc Davis. Resetting the Launch Services worked to resolve my issue. I had a similar issue but couldn't change the default app FROM mail to another client. It kept reverting back. Running through the reset process now has all of that working again, and my 'share' function in Safari is working with the proper mail client as well.

Execute this in Terminal:

/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchSe rvices.framework/Versions/A/Support/lsregister -kill -seed

Should have known. Restart solves many problems!

Thanks. That worked like a charm!

Have you found another solution? I currently have this problem. Thanks.

I was able to solve the problem using one of the solutions mentioned above in the thread. The way to do so is to go to Apple Mail --> Preferences --> General --> Default Email Reader and then in the Drop Down list, click 'Select' at the bottom and manually browse to Microsoft Outlook in the Applications folder.

THANK YOU! Easiest of the provided solutions and now works properly. not sure why your answer isn't the Apple Recommended answer.

Alright so this may seem crazy, but try deleting the .Spotlight-V100 folder on the root drive
sudo rm -Rf .Spotlight-V100/

(This will delete your Spotlight Cache)

Then kickstart spotlight's re-indexing with

sudo mdutil -E /

After that try setting the default mail client again.

This worked for me. My theory is that if spotlight is for some reason corrupt or not searching correctly Apple Mail isn't able to properly set the default Mail application. (It must be using spotlight to accomplish this somehow).

If this fixes it for anyone else I'd be very curious to know!

Hope this helps.

I also had this issue where Outlook could not be set - it kept defaulting back to Mail app every time I quit Mail.

I ran the command to reset LaunchServices: /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchS ervices.framework/Versions/A/Support/lsregister -kill -r -all local,system,user

...and when I opened Mail again and went into Preferences it correctly showed Outlook. This seems to have now stuck.

GO TO SYSTEM PREFERENCES AND CLICK ON EXTENSIONS. CHECK THE 1ST 2 AIRMAIL BOXES.

THEN OPEN APPLE MAIL (I MEAN THE APPLE DEFAULT MAIL APP). THEN OPEN MAIL AND THEN PREFERENCES. YOU WILL SEE THE DEFAULT EMAIL APPS. DO NOT CLICK ON ONE OF THE APPS. THIS DOES NOT WORK SO CLICK THE SELECT BUTTON OR BAR AND IT WILL OPEN YOUR APPLICATIONS FOLDER, THEN LOCATE YOUR AIRMAIL APP IN THE FOLDER AND DOUBLE CLICK ON THE APP AND THAT WILL SET IT TO DEFAULT FOR YOU.

Hi txredneckcub, Your answer was absolutely the most helpful of all that I read. I had set my default mail client to MS-Outlook when Mail was giving me problems. When I tried to set it back to Mail after Mail was fixed, it kept on reverting to MS-Outlook. So, per your advise, I went to Mail --> Preferences --> General --> Default mail reader drop-down --> Select...; then, I selected MS-Outlook from the Applications window. I then repeated the procedure, but, this time, I selected Mail from the Applications window and it worked! Thanks a million!

This helped me! So easy I didn't even think of it! Thanks!