Emails are randomly going into my Outbox when attempting to send them

Question

Hello,

Recently, I have been having issues with my emails. When sending them out, some are randomly being stuck in my Outbox. Most of the emails are not large and contain no attachments. I have also tried running an office repair (both quick and online repairs) and creating a new Outlook profile. Those fix the issue for a few days but then the issue comes up again. I still have a large amount of space available in my Outlook (over 35GB). Is there anything I can do to prevent this from happening?

I also tried to reopen the emails in my Outbox and try to re-send them but that doesn't work.

I tried to also select "Update folder" in Outlook to see if that would push the emails out but that did not work either.

Thanks in advance for any help.

Best,

Kareem

Answer 1

Hi Kareem,

Based on your sharing, since a new profile helps only temporarily, I suspect this issue is likely due to cached mode corruption, add-ins, sync state or third-party interference. To narrow down the situation, you can try these steps:

1/ Confirm Outlook is not offline and turn on "Send immediately when connected"

Refer to Outlook email stuck | Microsoft Support, for emails that stuck in Outbox:

• In classic Outlook, go to Send/Receive and make sure Work Offline is not enabled. Also check the bottom status bar for "Disconnected", "Trying to connect" or "Working Offline".
• Go to File > Options > Advanced > Send and receive > ensure "Send immediately when connected" is checked

2/ Test with Outlook Safe mode when the issue recurs

• Press Windows + R to open Run dialog and press outlook.exe /safe > OK to run
• If the issue does not happen in Safe Mode, the cause is likely due to an add-in
• Then go to File > Options > Add-ins > Manage COM Add-ins > Go > uncheck all listed add-ins and click OK
• Restart Outlook and check if the error is gone. Then re-enable the add-ins one by one and restart Outlook each time to find which one causing the error.

3/ Rebuild the Outlook cache

• Complete close Outlook and go to Control Panel > Mail > Email Accounts
• Select your account > Change > ensure it is using Cached Exchange Mode

• Close all the windows then press Windows + R to open Run dialog and type %localappdata%\Microsoft\Outlook > OK to run
• Locate the .ost file according to your mailbox and rename it to something like old-yourmailbox.ost
• Reopen Outlook and let it rebuild the cache

Please try these steps and let me know how or whether it works. If not, please feel free to reach out again in the comments on this post. I'm happy to assist you further and we can investigate together to find out a solution.

Thank you for your understanding and cooperation. I'm looking forward to your reply.

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