Microsoft Outlook not being set as the default email program for Windows or Mac OS. Jul 26, 2018 Choose Preferences from the Mail menu, then click General. Or, if you're prompted to set up an email account, add your account, then choose Preferences from the Mail menu. Choose your email app from the ”Default email reader” pop-up menu. You can also set your default email app in the preferences of your third-party email app.
Many people have multiple email accounts but tend to use them for different purposes. If you have multiple email accounts, you'll want to set the one you use most often as your default.
.You can search for an expression and use the n wildcard character to replace the search string with the rearranged expression. For example, search for to find 'presorted' and 'prevented.' Microsoft word search and replace mac pro.
On the Tools menu, click Accounts.
Tip: A list of your accounts is in the left pane of the Accounts box, and the default account is at the top of the list.
Select the account that you want to make the default account.
In the bottom, left pane of the Accounts box, click Set as Default .
To send an email message from an account other than your default account, under Inbox, select the account in the list. You can now send email from your non-default email account. When you're finished, under Inbox, click your default account.
When you forward or reply to a message, Outlook uses the account that the original message was sent to. To change this preference, on the Outlook menu, click Preferences, and then under Email, click Composing . Under Format and account, clear the Reply and forward using the default e-mail account check box.
Your default mail reader is what's used when you're browsing a web page and share it via email with a friend or colleague, or mail it to yourself for further reading. The Mac default is to use the Mail app, but you can change the default to Outlook.
Open Finder > Applications.
Select Mail.
Select Mail > Preferences.
On the General tab, in Default email reader, select Microsoft Outlook.
On the Tools menu, click Accounts.
A list of your accounts is in the left pane of the Accounts dialog box, and the default account is first in the list.
Select the account that you want to make the default account.
On the Action pop-up menu , click Set as Default.
Notes:
If you have configured multiple POP accounts, messages will be sent from the account that is currently selected, or the default account. To change the account from which a message is sent, select an account on the From pop-up menu in the email message. If you have added only one account to Outlook, the From pop-up menu is not available.
When you forward or reply to a message, Outlook uses the account to which the original message was sent. To change this preference, on the Outlook menu, click Preferences, and then under E-mail, click Composing. Under Format and account, clear the Reply and forward using the default e-mail account check box.
This article describes some useful tools for Microsoft Outlook for Mac.
The Outlook Search Repair tool repairs search results within Outlook.
Important
Due to some changes in macOS Mojave, this tool no longer works in 10.14 and higher. If you are on macOS Mojave (10.14), you can follow the steps below to reindex Spotlight for Outlook for Mac.
Choose Apple menu, then System Preferences, and then Spotlight.
Select the Privacy tab.
In Finder:
On the Go menu, select Go to Folder..
Copy and paste the following location into the 'Go to the folder:' dialog box and select Go:
~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/
Drag the 'Main Profile' folder to the Privacy tab. Once added, remove the folder, and Spotlight will re-index the folder.
You must perform this step for any additional profile folders you have.

See the following article from Apple to learn more: How to rebuild the Spotlight index on your Mac.
Use this tool if search results within Outlook show nothing or return older items only. For example, if you search for an email message that you already have open and that message isn't displayed in the search results.
Download and open the Outlook Search Repair tool.
Follow the instructions.
Note The tool searches for duplicate installations of Outlook. If no duplicates are detected, go to step 3. If duplicates are detected, remove the duplicate Outlook installations, and then restart the system. After your system is restarted, the Outlook Search Repair tool may reopen. If it does reopen, exit and restart the tool.
Select Reindex.
Note The Outlook Search Repair tool displays a 'Reindexing, please wait' message while it works. Wait for this process to finish. This may require an hour or more, depending on the size of your Outlook profile. Outlook doesn't have to be open when the repair occurs. A spotlight search will be slower and may not finish while the index is being repaired.
Exit the Outlook Search Repair tool when you receive the following message after the repair is completed:
Done! Reindexing has completed!
The Outlook Reset Preferences tool resets all Outlook preferences to their default settings.
Use this tool to reset any customizations that you've made to Outlook by using the Preferences option on the Outlook menu. This tool also stores the settings for the Outlook window size and position. This tool shouldn't be needed most of the time. But it can be useful.
Note The Outlook Preferences file doesn't contain all the preferences for the application. Also, resetting Outlook preferences doesn't remove email messages or account settings.
The Default Mail Application tool lets you easily make Outlook the default mail application.
Use this tool if you want Outlook to open a new email message when you click a mailto: link in an email message or on a website. Selecting a mailto: link opens the default email application. Outlook isn't the default email application until you change that setting.
The Reset Recent Addresses tool lets you reset recent addresses that Outlook stores. This tool deletes all recent addresses instead of you having to manually delete addresses one at a time.
When you compose an email message and add people on the To, Cc, or Bcc line, Outlook suggests names as you type characters. The list of names that Outlook uses is a combination of stored contacts, the company directory, and recent contacts. Recent contacts have an 'X' character next to each name. Without this tool, you have to click the 'X' on each contact to remove that contact from the Recent Address List. The Reset Recent Addresses tool cleans out all recent addresses at the same time.