Published 2023-09-05 by TechNet New England
Outlook for Mac has its own set of quirks separate from the Windows version. Connection issues, sync failures, and crashes are the most common problems. This guide covers practical fixes. ## Check the Basics 1. **Is your internet working?** Open Safari and load a website. 2. **Can you access webmail?** Go to [outlook.office.com](https://outlook.office.com) and sign in. If webmail works, the issue is the Mac Outlook application. 3. **Is Outlook updated?** Open Outlook, click **Help > Check for Updates** (or open Microsoft AutoUpdate). Install any available updates. ## Fix 1: Force Quit and Restart 1. Press **Command + Option + Escape** to open Force Quit. 2. Select **Microsoft Outlook** and click **Force Quit**. 3. Wait a few seconds, then reopen Outlook. ## Fix 2: Reset Outlook Preferences Corrupt preference files can cause Outlook to misbehave. 1. Quit Outlook completely. 2. Open **Finder**. 3. Press **Command + Shift + G** (Go to Folder). 4. Type: `~/Library/Containers/com.microsoft.Outlook/Data/Library/Preferences` 5. Move the file `com.microsoft.Outlook.plist` to your Desktop as a backup. 6. Reopen Outlook. It will create a fresh preferences file. If this fixes the issue, you can delete the backup file from your Desktop. If it does not help, move the file back. ## Fix 3: Remove and Re-add Your Account 1. Open Outlook. 2. Go to **Outlook > Settings > Accounts**. 3. Select your email account and click the minus button to remove it. 4. Click the plus button to add it back. 5. Enter your email address and follow the prompts. 6. Outlook will re-sync your email from the server. ## Fix 4: Clear the Keychain Entries macOS stores email credentials in the Keychain. Corrupt entries can block authentication. 1. Quit Outlook. 2. Open **Keychain Access** (search for it in Spotlight with Command + Space). 3. In the search bar, type "Exchange" or "Office" or "Microsoft." 4. Delete any entries related to your email account or Microsoft Office. 5. Reopen Outlook and sign in when prompted. ## Fix 5: Rebuild the Outlook Database For older versions of Outlook for Mac that use a local database: 1. Quit Outlook. 2. Open **Finder** and navigate to: `~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/` 3. You will see your profile folder. Hold **Option** and drag it to your Desktop to create a backup copy. 4. Delete the original profile folder. 5. Reopen Outlook. It will create a new database and re-sync from the server. Note: Modern versions of Outlook for Mac (the "New Outlook") use a cloud-based architecture and do not have a local database to rebuild. If you are using New Outlook and it is not working, try removing and re-adding the account. ## Fix 6: Check for macOS Updates Some Outlook issues are caused by macOS compatibility problems. Make sure your Mac is running a supported version of macOS. 1. Click the **Apple menu > System Settings > General > Software Update**. 2. Install any available updates. ## When to Contact IT Support Contact your IT provider if: You cannot sign in even with correct credentials (may be an MFA or conditional access issue). Outlook keeps crashing after trying all fixes above. Shared mailboxes or calendars are not syncing. You see certificate or security warnings when connecting.