When clicking on hyperlinks that are set to open a compose email message on OSX the Mail.app application will launch. Since it is likely that your preferred email application is something other than Mail.app such as Mozilla Thunderbird, Opera, Microsoft Outlook for Mac, Postbox, Sparrow, or something else then you will want to change the default email client to your preferred email application. In my case I use MS Outlook for the Mac so I needed to set the default email client to Outlook. Use the directions below to modify the default application that opens to compose email messages.
Modify Default Email Client On OSX From Mail.app To Outlook:
You will need to first launch Mail on your Mac by either performing an action that will launch the default email client to compose a message such as clicking on a hyperlink that links to mailto: or you can simply launch Mail from the Applications folder. If you have never opened Mail on your Mac then the configuration window to configure a new email account within Mail will launch as shown in the below image.
Welcome To Mail Configuration Windows On OSX Lion:
As you can see above the initial configuration window will begin the process of adding a new email account to the Mail application on OSX. There are only a couple items that need to be filled in to continue through the process until you can get to the Mail Preferences configuration window. On the first configuration window shown in the example window above simply put “email@example.com” into the Email Address field and then click the Continue button. Mail will then attempt to automatically obtain the email server settings though in our case it will not be successful. The next configuration window will display as shown in the below example image.
Welcome To Mail > Incoming Mail Server:
In the configuration window above add mail.example.com into the Incoming Mail Server field and click Continue. You may receive an error below the input fields but you can click the Continue button again to advance to the next step as shown in the below example image.
Welcome To Mail > Incoming Mail Security:
You don’t need to modify any settings in the configuration window above so click the Continue button to move to the next step which is shown in the image below.
Welcome To Mail > Outgoing Mail Server:
In the Outgoing Mail Server field enter mail.example.com and then click the Continue button. You will again receive an error message which is displayed below. The configuration steps complete some checking to verify your settings are correct such as attempting to connect to the outgoing server or SMTP server you have specified and if it is not reachable it will display the below warning message.
Welcome To Mail > SMTP Server Is Not Responding:
No need to worry as you can again click the Continue button in the above window to continue through the configuration steps so we can eventually get to the Mail Preferences configuration window and modify the default email client on the OSX computer we are working on. Once you click Continue the below Outgoing Mail Security configuration window will display.
Welcome To Mail > Outgoing Mail Security:
Don’t worry we are actually close to the final step in which we can change the default mail client! You don’t need to modify any settings in the above window so simply click the Continue button to finally display the Account Summary window as shown in the below example image.
Welcome To Mail > Account Summary:
Since we don’t care about the settings we have entered there is nothing to verify. Click the Create button to finish the account creation process and launch Mail on OSX. With the Mail application as the active window click on Mail in the top navigation window next to the Apple logo and select Preferences from the drop down as shown in the below example image.
OSX Mail Menu > Preferences:
Once you click on Preferences from the above drop down the Mail Preferences window will display on the General tab as shown in the below example image.
OSX Mail Preferences > General:
As you can see in the above example image of the Mail Preferences configuration window the top option that you can modify is called Default Email Reader. Click the drop down to select you preferred email client which for me is Microsoft Outlook as shown in the below example image.
OSX Default Email Reader Set To Microsoft Outlook:
Once you have modified the Default Email Reader to your preferred email client you can close the Preferences configuration window and then shut down the Mail application. Now when you click on a mailto hyperlink it will launch whatever email application you configured as the Default Email Reader which in my case is Microsoft Outlook for Mac.