Outlook not syncing emails

Summary

This guide helps you troubleshoot and resolve: Outlook not syncing emails. Follow the steps below to fix the issue.

Common Causes

Problem

Emails are not arriving in your inbox, or sent messages are not appearing in the Sent Items folder. Outlook may appear stuck or display an offline status.

Symptoms

• “Working Offline” shown in the status bar
• New emails do not appear
• Messages remain in the Outbox
• Error messages about server connection

Solutions

Step 1: Check Outlook Mode

1. Look at the bottom-right of Outlook – does it say “Working Offline”?
2. If yes, go to the Send/Receive tab and click Work Offline to toggle it off. The button will change to “Send/Receive All”.

Step 2: Verify Internet Connection

1. Open a web browser and load any website.
2. If pages do not load, resolve the internet issue before continuing.
3. If you are using a VPN, ensure it is connected and not blocking Outlook traffic.

Step 3: Ensure Outlook and Windows Are Up-to-Date

1. Open Windows Settings → Update & Security → Windows Update and install any pending updates.
2. Open any Office application, go to File → Account → Update Options → Update Now to apply the latest Office updates.

Step 4: Verify Account Server Settings and Credentials

1. Open Outlook and go to File → Account Settings → Account Settings. Select your email account and click Change to review server settings (Exchange, IMAP or POP).
2. Note: Control Panel → Mail may not be available in Click-to-Run or Microsoft 365 installations. Use the Outlook File menu path above instead.
3. Confirm the incoming and outgoing server names, ports, and encryption match your organization’s specifications. See Setting Up an Email Account in Outlook (POP/IMAP/Exchange) for details.
4. Re-enter your password if prompted, and test the account settings.

Step 5: Check Mailbox Size and Quota

1. In Outlook, go to File → Info → Tools → Mailbox Cleanup → View Mailbox Size.
2. If the mailbox is near or exceeds its quota, archive or delete old items, or ask your IT administrator for additional storage.

Step 6: Start Outlook in Safe Mode and Disable Problematic Add-ins

1. Close Outlook.
2. Press Win + R, type outlook.exe /safe, and press Enter.
3. If Outlook syncs correctly in Safe Mode, an add-in is likely causing the issue.
4. Go to File → Options → Add-ins, select COM Add-ins and click Go. Uncheck any non-essential add-ins, then restart Outlook normally.

Step 7: Repair Outlook Data Files (PST/OST)

1. Close Outlook.
2. Navigate to %localappdata%\Microsoft\Outlook and locate your .pst or .ost file.
3. Locate scanpst.exe (Inbox Repair Tool). The path depends on your Office installation:
   • Click-to-Run (Microsoft 365 / Office 2019+): Check C:\Program Files\Microsoft Office\root\Office16\ or C:\Program Files (x86)\Microsoft Office\root\Office16\.
   • MSI (volume licensed Office): Check C:\Program Files\Microsoft Office\Office16\ or C:\Program Files (x86)\Microsoft Office\Office16\.
4. Double-click scanpst.exe, browse to your data file, and follow the wizard to repair it.
5. For more information, see Backing Up and Restoring Outlook Data Files (.pst/.ost).

Step 8: Check Cached Exchange Mode Settings

1. In Outlook, go to File → Account Settings → Account Settings, select your Exchange account and click Change.
2. Ensure Use Cached Exchange Mode is enabled. If it is already on, try reducing the “Mail to keep offline” period or temporarily disable it to force a full sync.

Step 9: Clear Outlook Cache

1. Close Outlook.
2. Press Win + R, type %localappdata%\Microsoft\Outlook, and press Enter.
3. Rename the RoamCache folder to RoamCache.old instead of deleting it. This allows you to restore it if needed.
4. Restart Outlook and allow it to rebuild the cache.

Step 10: Verify Firewall and Antivirus Settings

1. Open your firewall or antivirus console.
2. Ensure that Outlook (or outlook.exe) is allowed to communicate on ports 443 (HTTPS) and 993/995 for IMAP/POP, or the appropriate Exchange ports.
3. If you must test with protection disabled, turn off the firewall/antivirus temporarily, test Outlook, then re-enable it and add the proper exceptions.

Step 11: Repair or Create a New Outlook Profile

1. Press Win + R, type control, and press Enter.
2. Open Mail → Show Profiles. If Mail is not available, use File → Account Settings → Manage Profiles in Outlook.
3. To repair, select your profile, click Properties, then Email Accounts and choose Repair.
4. To create a new profile:
• Click Add, give the profile a name (e.g., “Outlook-New”).
• Enter your email address and password, then follow the wizard.
• Set “Always use this profile” and select the new profile.
5. Open Outlook with the repaired or new profile and verify syncing.

Step 12: Check Server Status

1. Visit your organisation’s IT status page (if available) to see if there are known Exchange or Outlook service issues.
2. If a service outage is reported, you will need to wait for the issue to be resolved.

When to Contact IT Support

Contact IT Support if:

• You have completed Steps 1 through 12 and emails are still not syncing.
• You see repeated server connection errors after verifying your internet connection.
• You are uncomfortable backing up or repairing data files, or disabling security software.
• Your organisation reports a known Exchange or Microsoft 365 service outage.

As a managed service client, please raise a ticket within 24 hours if the issue is affecting your ability to send or receive critical business email.

Need More Help?

If emails still aren’t syncing, Open a Ticket with IT Support and include:

• Whether “Working Offline” is displayed
• Any error messages shown
• The steps you have already tried

Still Having Issues?