I'm on OSX el Capitan (10.11.6).

I use Outlook to access my email and would like outlook to be the default mail application. All the instructions I find online suggest that I should open mail and choose "Mail -> Preferences" to set the default mail app. Unfortunately Preferences is greyed out until an account is added. I don't have another account that I want to add to my Mac.

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How can I set the default mail client to Outlook without adding an account to the mail client?


The simplest way to do this - which doesn't involve messing with Mail itself - is the old faithful RCDefaultApp
Yes it's ancient; yes it still works; yes it's free.

It installs as a control panel from where you can set defaults for just about anything on the machine... including Mail.

Simply select from a drop menu

enter image description here

If you want to have a poke at the other sections, note it can take some time to build the apps/services list; don't think it's hung, it's just thinking ;-)

  • Does this work with Mac OS X High Sierra? Aug 20 '18 at 14:43
  • 1
    Yes, & still works on Mojave beta.
    – Tetsujin
    Aug 20 '18 at 14:44
  • For anyone looking to use Gmail (inside of Firefox) as their default e-mail client, do this: 1) set your browser as the default application for e-mail; 2) Go to Firefox's preferences, look for mailto to find the relevant Applications preferences, there, select Use Gmail in the dropdown list. Dec 14 '18 at 18:47
  • Yes & it works on GA Mojave (10.14.4) May 9 '19 at 18:15
  • 1
    SwiftDefaultApps has superceded RCDefaultApp, see apple.stackexchange.com/a/400128 Aug 27 '20 at 6:21

I finally found something easy that worked, the SetDefaultMailApp from Microsoft:


  • 4
    works like a charm. Dec 10 '18 at 22:45
  • 7
    Thanks, this was the solution for us. The accepted answer to use RCDefaultApp is still valid but likely less-so in some larger corporate environments. Cheers! Aug 27 '19 at 17:15
  • Works on Mojave Oct 10 '19 at 15:11
  • This worked for switching to Spark. With Spark installed, the drop-down in SetDefaultMailApp includes com.readdle.smartemail-Mac.
    – Nick Edgar
    Apr 15 '20 at 19:51

You can use the system-installed Python interpreter to quickly change the default mail app.

Copy/paste the following command into Terminal, replacing com.microsoft.Outlook with the application bundle identifier for your mail app. Outlook's bundle identifier is com.microsoft.Outlook.

/usr/bin/python2.7 <<EOF
import LaunchServices;
result = LaunchServices.LSSetDefaultHandlerForURLScheme(
print("Result: %d (%s)" % (
    "Success" if result == 0 else "Error"))

If you're not sure what the bundle identifier is for your mail app, run osascript -e 'id of app "Some App Name"' to find it. For example, osascript -e 'id of app "Mail"' returns com.apple.mail.

  • 3
    Works fine on Mojave. May 15 '19 at 11:18
  • Thanks! Works perfectly.
    – Jonas H.
    Nov 12 '19 at 14:09
  • I like this the best because (a) it does not require installing any additional software, and (b) I tend to like any solutions that use Python :-D
    – Steve
    Dec 9 '20 at 18:21
  • Is there not a simple system properties text file somewhere we can just open in whatever editor for this? I get using an official api is nice, but I figure it's just serialized down to a simple utf8 key-value string in some file... Jun 8 at 14:55

SwiftDefaultApps seems to have superceded RCDefaultApp, which stopped working due to OSX changes, and the domain is down too.

brew cask install swiftdefaultappsprefpane

The easiest solution is to use MSFT Mail Changer app for Mac.

You can download it from the page at this link.


Just download the .app file, no install, it gives you a list of registered mail clients, you pick one and done.

My company security (JAMF policy) blocks access to even open apple mail but didn't make this change so none of the share file commands from Word, Excel, or PPT would work. This app does the trick.


I know it's an old question, but I needed to do the same, possibly from command-line, and I found a solution.

You will need Homebrew, which can be installed with:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Then, you will need duti, which is available through Brew:

brew install duti

Now, we need to find out the name of the mail application you want to set as default, we can do that running the following command (change Airmail with your desired mail client):

mdls -name kMDItemCFBundleIdentifier -r /Applications/Airmail\ 3.app
# this will return "it.bloop.airmail2"

Now, we can set our desired app as default mail client with:

duti -s it.bloop.airmail2 mailto

That's it!

  • EDIT: I was mistaken. This seem to have the same effect as Microsoft's "Default Mail Application" application so is a suitable answer
    – velkoon
    Aug 2 at 16:18

If you don't want to install any third-party apps, one solution is to just add a junk mail account:

enter image description here

It will first try to connect for about a minute and fail. But afterwards you can click on "Sign in" again and it will close the accounts dialog, allowing you to change the Preferences.


Sometimes, even after setting Outlook as default mail client in Apple Mail - with an account you remove afterwards - (how could Apple ever think this is a good place to stick this setting) it does not stick.

Just to be sure, after setting the pref in Mail, run this through Terminal:

  LaunchServices.framework/Versions/A/Support/lsregister -kill -r -all local,system,user
  • Honestly, putting the setting there seems like an evil monopoly move to me... force people to setup the macOS Mail client before they're allowed to actually switch to using another mail client. It'd be like if Safari, Internet Explorer, or Edge required you to sign into some accounts, give it some credentials, and set up some bookmarks and a homepage before it would let you set Chrome or Firefox as the default browser. If using native mail clients on a computer wasn't so odd (everyone just uses gmail or other webmail it seems), we'd see antitrust lawsuits over this... Jun 8 at 14:50

Sometimes the easiest solutions stare us in the face and it's easy to overlook them. I get asked this regularly and the easiest way to do this is to just set up Apple Mail with your email account and then change the default email application to Outlook.

You don't have to use Apple Mail again after that. So, while you're technically still adding an account to Mail, you don't have to use it, or you can remove it after you've set the default to Outlook.


I just wanted to add that in some cases, certain Apple software (e.g. Photos) have their own settings for which email client to use when sharing content. So you will need to select Outlook as the default within these Apps as well if you want to share content via email.

  • 6
    This doesn't answer the question since it requires adding an account. What I would like to know is where the internal setting is in OSX to get control over this without the requirement of adding an account. BTW, my comment explains how to do the same thing without needing a "real" account. Nov 21 '16 at 22:01
  • Ah, I didn't pick up on your comment while adding my answer. For future reference it's better to edit your question to provide additional context, rather than adding a comment. I do realise you asked how to change the default without adding an account to the mail client, hence my answer stating you didn't have to use Mail afterwards (or even keep the account in it) after changing the default. Now that I've read your comment, is the reason you're asking this because you're having trouble making sure the change 'sticks' by using this option? If so there is a potential fix for this.
    – Monomeeth
    Nov 21 '16 at 22:37
  • It also won't let you add an account without downloading all your email. Because of the way Mail treats labels (as folders) it would take about 100 GB to retrieve my email. Oct 30 '20 at 19:03

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