Outlook ran out of storage

Use Mailbox Cleanup to trim your mailbox size:

1. In Outlook, click File > Tools > Mailbox Cleanup.
2. Select your preferred clean up option.

Maintaining your Outlook inbox

Follow these best practices to keep your mailbox from running out of space. Make sure to backup your inbox first to prevent losing important mail.

1. Empty your Deleted Items and Junk Email folders regularly.
2. Archive older items: Setup your archive preferences under Info > Cleanup Tools > Archive. Archived items will be removed from your inbox and added to the archive.pst file per your settings.
3. Go to File > Info > Cleanup Tools > Mailbox Cleanup and choose View Mailbox Size. Choose the option to Find older or larger items to delete or archive.
4. Save attachments to your computer or cloud storage and then remove them from Outlook.

Outlook error message: "Not recognized as a valid sender"

The most common reason for this error is that your email address is suspected of sending spam and it's no longer allowed to send messages outside of your organization. Contact your email admin or IT for assistance.

Outlook freezes after clicking signature button

To solve this issue, uninstall the pre-installed Microsoft Office Desktop Apps:

1. Right click the Windows Start button and click Settings.
2. Click Apps > Apps > Features.
3. Choose Microsoft Office Desktop Apps and click Uninstall.
4. Restart your PC.
5. Run a repair of Office to make sure everything gets fixed.

If the above doesn't work, follow these steps to remove Office setup registry keys that still incorrectly remain in the registry:

1. Press the Windows key + R to open a Run window.
2. Type "regedit" and click OK.
3. Press CTRL + F and enter 0006F03A-0000-0000-C000-000000000046 into the search box, then click Find Next.
4. Delete the key: right-click the entry and click Delete.
5. Press F3 to repeat the search until no more registry keys are found.

Outlook won't open

If you are having trouble starting Outlook, try the following. After each, check if the issue is resolved.

Start Outlook in safe mode (on a PC):

1. Click Start > Run.
2. Type "Outlook /safe", and choose OK.
3. In the Choose Profiles dialog box, Profile Name should be "Outlook" by default. Choose OK.
4. If prompted, enter your password and choose Accept.

Create a new Outlook profile (on a PC):

1. Open the Control Panel. Choose Mail, then in the following dialog box choose Show Profiles > Add.
2. In the Profile Name box, type the name you want to use for your new profile. Choose OK.
3. Fill in the Auto Account Setup page with your name, email address, and password. Choose Next.
4. Choose Finish and you'll find the new profile name you added listed on the General tab in the Mail dialog box.
5. Under When starting Microsoft Outlook, use this profile, choose Prompt for a profile to be used, and then choose OK.
6. Restart Outlook. In the drop-down list in the Choose Profile dialog box, choose the new profile name you created. Choose OK.

Run the Inbox Repair Tool to scan your data files and repair errors:

1. Exit Outlook to use the Inbox Repair Tool.
2. See instructions here for Outlook 2016 and 2013, and here for Outlook 2010.

Outlook won't receive new emails

If you aren't receiving new emails, try the following. After each, check if the issue is resolved.

1. Make sure you aren't in Work Offline mode by checking the status bar at the bottom of your Outlook window. If you are in Work Offline mode, go to the Send/Receive tab and click "Work Offline" to disable it.
2. Make sure you are connected to the internet.
3. Try restarting Outlook by closing and reopening it.
4. Check if mail is ending up in the junk folder (or the "other" section if you are using Outlook.com).

Outlook won't send emails

If you are experiencing issues sending email, try the following, then try sending again.

1. Resend the message: If the message is stuck in the outbox, move it to the Drafts folder. Open the email in Drafts and click Send. Check for the mail in the Sent folder.
2. If the lower right corner of the Outlook window indicates you are Disconnected, Working Offline, or Trying to Connect, you are offline. Click Send/Receive > Work Offline. Outlook should now indicate you are Connected to Server.
3. Ensure any file attachments do not exceed 20MB.
4. If you have recently changed your Microsoft password, you'll need to update it in Outlook as well: Click File > Account Settings > Account Settings. Select the Email tab, choose your account and click Change. Update your password then click Next > Close > Finish.

Outlook missing archive folder

If your archive folder is missing from Outlook, try the following. Check for the folder again after each.

1. Collapse the mailboxes and folders in the left pane to reduce the number of items displayed.
2. Click Send/Receive All Folders on the Send/Receive tab.
3. Check the trash in Outlook as well as your computer's trash in case the folder was accidentally deleted.
4. Repair Outlook using Microsoft's built-in utility:
   • Close all Microsoft Office applications.
   • Type Apps & Features into the Windows search box. Select Apps & Features.
   • Find and click Microsoft Office in the list of installed apps and features.
   • Choose Modify > Yes if prompted "Do you want to allow this app to make changes to your device?"
   • Choose Online Repair > Repair.

Outlook missing Scheduler

If the Scheduling Assistant or Resource Scheduler is missing, try the following.

1. In Outlook, click File > Options > Customize Ribbon.
2. Under Main Tabs, ensure the box by Appointment is checked and click Reset.
3. If the issue persists, go back to Customize Ribbon. Select "Appointment" in the Main Tabs box and click New Group to create a new group under the Appointment ribbon.
4. Ensure "All Commands" is displayed in the "Choose commands from" dropdown. Find "Scheduling" and select it. Click Add to add it into the new group you created in step 3.
5. Check if issue has been resolved.

Outlook calendar not syncing

On the Outlook app (check if issue is resolved after each):

1. Go to Calendar in your Outlook app and tap the three lines in the upper left corner. Under your email address, ensure Calendar is selected.
2. Ensure that access to Contacts is enabled for Outlook:
   • iOS: Open your device's Settings. Scroll down and tap Outlook > Contacts and ensure Background App Refresh is enabled.
   • Android: Open your device's Settings. Tap Applications > Outlook and ensure Contacts is enabled.
3. Reset your account: In the app, tap the gear icon. Tap the account you want to sync > Reset Account.
4. Re-add your account: In the app, tap the gear icon. Tap the account you want to sync. Tap Delete Account > Delete from this device. Re-add your email account.

On the Gmail app (check if issue is resolved after each):

1. If you are seeing the message "Unable to sync calendar and contacts" in your notification bar, tap this message. Tap Allow and follow the prompts.
2. Go to Settings > Accounts > Exchange and tap the email address you want to sync. Ensure Sync Calendar is enabled. This may take a few minutes to take effect.

On iOS Mail (check if issue is resolved after each):

1. Go to your device's Settings > Accounts & Passwords and select the account you want to sync. Ensure Calendars and Contacts are enabled.
2. Re-add your account: go to your device's Settings > Accounts & Passwords and select the account you want to sync. Tap Delete Account. Choose Exchange when re-adding your email.

Outlook mobile not syncing

Try the following. After each, check if the issue is resolved.

1. Ensure your internet connection is stable. Open other apps and check that those can access the internet. If you are experiencing connection issues, resolving those should resolve the Outlook sync issue.
2. Reset your Outlook account on your mobile device:
   • In the Outlook app, open the menu. Tap the gear icon to go to settings.
   • Find and open the Microsoft account you want to sync.
   • Scroll down and tap Reset Account.
3. Remove the account and add it again:
   • In the Outlook app, go to settings. Find and open the account you want to sync, and choose Delete Account.
   • Add the account again and check if issue is resolved.

Outlook missing Webex add-in

If you are missing the Webex toolbar in Outlook, try the following. After each, check if the issue is resolved.

1. In Outlook, go to File > Options. Select Add-ins.
2. In the Manage drop-down, select Disabled items and click Go.
3. In the Disabled Items window, select the Webex add-in and click Enable. Click Close and OK to return to Outlook.
4. Restart Outlook.

If Webex does not appear in the Disabled Items window, try the following:

1. In the Webex Meetings desktop app, go to Settings > Preferences and click the Calendar tab.
2. Check the Microsoft Outlook box and click Apply.

If the Webex toolbar still does not appear, try uninstalling then re-installing the Cisco Webex Productivity Tools App. Restart Outlook.

Outlook PST files missing

Try the following. After each, check if the issue is resolved.

1. Ensure that the network server where the PST file is located is available. If the network server is down, wait until it becomes available then check again for the PST file.
2. Check if the AutoArchive feature is enabled. If it is, check the AutoArchive file for missing PST items. This can be done in File > Options > Advanced > AutoArchive Settings.
3. Run Outlook's built-in Inbox Repair Tool:
   • Locate scanpst.exe. On a PC, it would generally be in the Program Files > Microsoft Office folder, though you may have to search for it within subfolders.
   • In the Inbox Repair tool, type the path and file name of your PST file or select Browse to locate the file by using the Windows file system, and then select Start. For Outlook 2010, 2013, 2016, 2019 and Office 365, the default file path for your PST file would be C:\Users%username%\Documents\Outlook Files. For 2007 and older, the default is C:\Users%username%\AppData\Local\Microsoft\Outlook.
   • Click Start to run a preliminary analysis. If errors are found, ensure the option to create a backup of the PST file is enabled and click Repair.

Outlook is slow

If Outlook is slow, try the following. After each, check if the issue is resolved.

Configure Outlook options:

1. In Outlook, choose File > Options > Advanced.
2. Go to Display and check "Disable hardware graphics acceleration". Click OK.

Try running a Microsoft Support and Recovery Assistant check:

1. Install the Outlook Advanced Diagnostics tool.
2. When prompted, click Run.
3. (When the report is generated, review the items on the Issues Found tab and do what is needed to remedy the issue.
   NOTE: For configuration details about Outlook, Windows, and your computer, review the settings on the Detailed View tab.

If Outlook is still slow, make sure your computer meets the system requirements for the version of Office that you are using, and consider upgrading.