In new Outlook, emails stay in the outbox even though they've been sent.

I tried disabling Viva Insight add-in but unfortunately that did not help. I still have a message in the Outbox in Outlook (New). I even right-clicked on the Outbox and selected Empty Folder from the menu. Even though it appears to delete emails from the Outbox, next time you open Outlook the message is back in the Outbox. I also tried to Repair and Reset the Outlook app one more time after disabling the Viva Insight, but the message is still there. This is a nasty bug.

I have the same issue with one message in the Outbox even through it was already sent. The recommended steps to reset Outlook and clear the cache did not solve the problem. Waiting for a resolution.

It also didn't work for me. I raised a case instead and they said to disable the viva insight add-in for Outlook. I haven't been able to test it yet but if you want to try, they said to open viva insight (easiest to open through teams for me), then press the 3 dots in the top right corner and go to settings > privacy > disable 'Insights Outlook Add-in'.

We're also experiencing a similar issue. There is one email that is stuck in the outbox folder that keeps reappearing whenever it is deleted. The stuck outbox email only appears when viewing the user's mailbox in the new Outlook client.

I tried following the steps provided by Md Feroz Mahmud MSFT, but the issue still persists. I repaired, reset, cleared cache, and removed and readded the email account.

I think the issue is being caused by the outbox folder, since research I am seeing from Microsoft says that the drafts folder replaced the outbox folder in the new Outlook client. When sending emails from the affected mailbox in the new Outlook, I can see the message staged in drafts and then send successfully. But an entry will appear as "queued" in the outbox folder after it is sent. These "queued" emails never leave the outbox folder, but we are able to delete them. Just not the one which will always reappear whenever the outbox folder is reloaded.

Microsoft Outlook Version 1.2024.612.

Client version: 20240614008.13

WebView2 Version: 126.0.2592.68

Hello Sharna Iveson,

Thank you for reaching out to the Microsoft Community. I'm sorry to hear that you're experiencing this issue with the new Outlook. Based on the troubleshooting steps you've already taken, it seems that primary troubleshooting has been completed. Here are a few additional steps you can try:

1. Check your internet connection: Ensure that your internet connection is stable and strong.
2. Repair New Outlook:
   • Type "settings" in the search box and select the Settings app from the results.
   • Select Apps > Installed apps, then type "Outlook" in the search box.
   • Locate the Outlook (New) app from the results, select the More options button (…), and then select Advanced options.
   • In the Reset section, select Repair.
   • Restart New Outlook.
3. Clear Cache and Restart (New Outlook):
   • Follow the same steps as above, but in the Reset section, select Reset instead of Repair.
   • Restart New Outlook.
4. Clear Outlook Cache: The Outlook client stores cache files to improve your overall emailing experience. Clearing this app cache may resolve issues such as failing to see email attachments. Clearing the Outlook cache won't delete your emails, contacts, or any other information saved in the app. Outlook will rebuild this cache as you use the app.
   • Open the Windows Run dialog box by pressing Windows+R.
   • Type %localappdata%\Microsoft\Outlook\RoamCache and press Enter.
   • The Outlook cache folder will open. Select all files by pressing Ctrl+A. Then, right-click on a selected file and choose "Delete".
   • Launch Outlook.

If the issue persists after performing these recommendations, it would be best for your current scenario to be diagnosed by Microsoft's frontline support team by collecting some more advanced logs information via remote session. Frontline technical support engineer can also involve specific support team for further analysis some particular situation if it is required. 

Since we forum moderators have limited permissions and access resources, due to this reason and for data privacy of users, we are unable to collect certain kind of logs information in the public forum. 

After diagnosing the scenario, our technical support team can provide possible information from their end. 

If there are any known issues, this information can be provided by the technical support engineer from their backend resources. 

For the above provided standard process information, in your organization, Office 365 global admin person may need to contact Office 365 support team on backend via an open service request so they can diagnose this specific scenario through some more technical resources, 

For this standard process, here's the official document for the global admin reference: Get support - Microsoft 365 admin | Microsoft Learn****(Online Option). 

Note: If you are an end-user person, you may need to contact the Office 365 global admin person in your business organization for connecting with technical support engineer for further process. 

Important note: If any organization's Office 365 Business/Business/Education subscription is from a syndicated partner or reseller, and if the global admin can't open the service request on their end, they may need to contact the reseller's support provider so they can help the global admin to open the service request on their end. after the Office 365 support team will involve in the created service request. 

Your cooperation precious time is highly appreciated. 

Sincerely

Feroz Mahmud | Microsoft Community Moderator