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Methods to Fix Outlook for Mac crashing on Launch! – Tutorial [2026]

admin | outlook for mac | 7 minutes read | Modified on: 14-01-2026

The article here highlighted detailed discussion to fix Outlook crashing on Mac, reasons behind it and how to avoid it in future. If you are facing the same situation, then read the article completely and go through the situations mentioned below.

Note. Before resolving the error, save unsent emails or drafts in a text file or an external application to avoid loss of data during maintenance.

Method 1. Restart Microsoft Outlook and macOS

Restarting Outlook will fix temporary errors by resetting system processes –

  • Close Microsoft Outlook (also check it is not running in the Dock).
  • Wait 60 seconds.
  • Run Outlook again.
  • If crash continues, restart Mac by navigating to Apple menu and click Restart.

Method 2. Update Outlook, macOS, and Microsoft Office

Outdated software can the main cause of Outlook for Mac crashing on launch and to resolve it follow the below steps –

Update Outlook and Microsoft Office –

  1. Run Outlook.
  2. Navigate to Help and click Check for Updates.
  3. Install the updates available and restart Outlook.

Update macOS

  1. Go to Apple menu, click System Settings, select General and click Software Update.
  2. Install Updates and reboot Mac machine.

Method 3. Open Microsoft Outlook in Safe mode

Safe mode disables add-ins as well as custom settings, helping isolate crash causes.

  1. Close Outlook
  2. Press the Option key and go to Outlook icon displaying in the Dock.
  3. Continue holding option until Outlook launches.
  4. Check Outlook’s stability in Safe mode.

If Outlook runs smoothly, then proceed to disable add-ins or reset settings.

Method 4. Turn off Add-ins

Installed third-party add-ins may be the cause of Outlook crashing on Launch.

  1. Run Outlook in Safe mode if required.
  2. Navigate to Tools and select Manage Add-ins.
  3. Uncheck the entire list of add-ins.
  4. Restart Outlook in normal mode.
  5. Enable add-ins again one-by-one, testing Outlook after each to identify the problematic add-in.
  6. Keep damaged add-ins disabled or check for updates on the provider’s website.

Method 5. Clear Outlook cache

Excessive cached data can destabilize Outlook.

  1. Close Microsoft Outlook.
  2. Open Finder and press Command + Shift + G.
  3. Enter ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook Preferences/
  4. Tap Go.
  5. Transfer Cache files to a backup folder on desktop.
  6. Launch Outlook again and build the cache.

Method 6. Reset Outlook Preferences

Corrupted preference files lead to crash.

  1. Close MS Outlook.
  2. Go to Finder and press Command + Shift + G.
  3. Type ~/Library/Preferences/ and tap Go.
  4. Locate & transfer files saved with com.microsoft.outlook to a backup folder.
  5. Launch Outlook again to restore default preferences.

Method 7. Repair Outlook Database

Corrupted database is a common trigger for Outlook crashing. To repair the same, follow the below steps –

  1. Close MS Outlook.
  2. Go to Applications, select Microsoft Outlook and click Microsoft Database Utility.
  3. Choose main identity.
  4. Click Rebuild and wait until process completes (large mailboxes will take time).
  5. Re-launch Outlook.

Method 8. Configure new Outlook profile

A corrupted profile needs replacement –

  1. Go to System Settings. Navigate to Control Center and select Microsoft Outlook Profile Manager.
  2. Click + icon to set up new profile.
  3. Set new created profile as default.
  4. Launch Outlook and add email accounts again.

Note. Redownloading email files need stable internet connectivity.

Method 9. Reduce Mailbox Size

Huge mailboxes will affect Outlook’s resources –

  1. Run MS Outlook.
  2. Navigate to File and select Archive.
  3. Transfer old emails to local folder and export them into .olm file.
  4. Make sure to keep mailbox under 10 GB.
  5. Start Outlook again.
Method 10. Check if there is any Malware present

Malware can interrupt Outlook’s performance –

  1. Install popular and recommended antivirus software (e.g. Malwarebytes for Mac).
  2. Run complete scan and delete detected threats if present.
  3. Restart Mac and launch Outlook again.
Method 11. Verify Network Stability

Inappropriate internet connection can result in syncing issues and crashes.

  1. Check internet connectivity by loading a website or through video streaming.
  2. In case of any unstability, restart router or switch to a wired connection.
  3. Open Outlook, navigate to Send/Receive and click Work Offline, then move back to online mode after the connection is stabled.
Method 12. Fix Font Conflicts

Corrupted or incompatible fonts can also lead to Outlook for Mac crashing on launch error. To resolve the same, use the below steps =

  1. Go to Spotlight search to open Font book.
  2. Choose all fonts and navigate to File, then click Validate Fonts.
  3. Delete or turn off flagged fonts.
  4. Restart Microsoft Outlook.
Method 13. Track System Resources

Not enough memory, CPU, or disk space can also lead to crashes.

  1. Use Spotlight search to open Activity Monitor.
  2. Test Memory, CPU, and Disk tabs to track the usage.
  3. Close unnecessary applications.
  4. Ensure to keep the disk space free by 10% (delete any unnecessary files if required).
  5. In case resources are constantly low, then upgrade your RAM or storage space.
Method 14. Reinstall Microsoft Outlook

Reinstalling Outlook will deliver a clear slate for constant issues.

  1. Close Microsoft Outlook.
  2. From Applications, drag the Outlook app to the Trash.
  3. Delete files from Trash.
  4. Download the new Outlook version from the Microsoft website or via Mac App Store.
  5. Install Microsoft Outlook and re-add email accounts.
Method 15. Reconfigure Keychain Access

Corrupted credentials of Keychain can get in the way with Outlook authentication.

  1. Open Keychain Access through Spotlight search.
  2. Navigate to Keychain Access, go to Preferences, and click Reset My Default Keychain.
  3. Add email accounts again in Outlook by mentioning their credentials in required fields.
  4. Start Outlook again.
Method 16. Check using New User Account

System-wide issues can create issues in Outlook.

  1. Navigate to System Settings, Users & Groups.
  2. Configure new email account with admin rights.
  3. Log in to the new created account and configure Outlook.
  4. If Outlook runs seamlessly, transfer your data to the new account or fix your original account using Disk Utility.
Method 17. Run Disk Utility
  1. Drive errors can lead to application crashes.
  2. Run Disk Utility using Spotlight search.
  3. Select the startup disk and go to First Aid, then click Run.
  4. Fix any discovered errors and start your Mac again.
  5. Launch MS Outlook again
Knowing why Outlook for Mac crashing on Launch

Outlook crashes can occur from many technical issues. Here are some common reasons discussed why Outlook for Mac keeps crashing –

  • User Profile Corrupted: The Outlook profile, at times becomes corrupted, lead to instability.
  • Old Version Software: Incompatible Outlook versions, macOS, or MS Office can cause Outlook crash on launch.
  • Large Size Mailbox or Cache: Large mailboxes or cache files may consume Outlook’s resources.
  • Damaged Add-ins: Conflicted third party add-ins can affect Outlook performance.
  • Corrupt Database: The database with organized emails and attachments at times become damaged, especially after instant shutdowns.
  • Inadequate System Resources: Low memory, drive space, or CPU can affect Outlook’s functioning.
  • Malware or Viruses: Harmful software may interrupt Outlook’s operations.
  • Corrupted Settings or Preferences: Damaged or incorrect configuration files can cause crashing error.
Troubleshoot to Avoid Future Crashes

Follow these strategies to maintain Outlook’s stability:

Install Regular Updates
  • Check for monthly updates and update Outlook, MS Office and macOS accordingly.
Manage Mailbox Size:
  • Take regular email backup to local folders or .olm files.
  • Try to keep mailboxes under 10 GB.
Backup Emails:
  • Export emails to an .olm file by navigating to File> Click Export.
  • Restore backup on an external drive or cloud service (e.g., OneDrive, iCloud).
Limit Add-ins:
  • Install verified, necessary add-ins and update them regularly.
Track System Health:
  • Make use of Activity Monitor to ensure sufficient memory, disk space, and CPU.
  • Make sure to free 10% of the disk space.
Run Antivirus Scans:
  • Perform monthly scans to detect and remove malware.
  • Keep Network Connections secure.
  • Use stable, high-speed internet for email syncing.

Backup Tip: Cloud backups are convenient but need solid security (such as two-factor authentication) to prevent unauthorized access. Local backups are stored offline and secure but require weekly updates to stay up to date.

Understand Specific Crash Scenarios

Tailor your approach based on the crash pattern:

  • Crashes on Launch: Use Safe Mode, disables add-ins, repairs the database, or reset preferences.
  • Crashes during Email Sync: Clear cache, reduces mailbox size, or stabilizes the network.
  • Crashes with Attachments: Check attachments in another application to check for corruption.
  • Irregular Freezes: Track system resources, shut background apps, or fix font conflicts.
  • Crashes after Sending Emails: Check Keychain Access or verify SMTP settings in Outlook, go to Preferences, click Accounts.

If the problem continues, then contact Microsoft Support or any certified Mac technician for advanced diagnostics, such as hardware testing or log analysis.

Additional Resources
  • Microsoft Support: Go to support.microsoft.com for Outlook-explicit guides & live chat.
  • Community Forums: Explore forums such as Reddit’s r/Office365 or Microsoft Community to find solutions shared by users.
  • Log Analysis: Use Console (via Spotlight) to view crash logs for particular error codes, which can assist you for further troubleshooting.
Conclusion

Outlook crashing is an annoying issue that interrupts the workflow. We expect the solutions discussed in the article were helpful in resolving Outlook keeps crashing on Mac. However, the continuous backups and hands-on maintenance is the key to avoid Outlook crashing during launch in the future. The best way to backup Outlook for Mac data files is by making use of MacMister OLM Converter for Mac & Windows. It is an app that download and save .olm files into numerous saving options such as PST, EML, HTML, DOC, Yahoo Mail, Office 365, and more.