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

One potential fix which I haven't seen mentioned here yet, is to disable Offline mode under Settings > General > Offline.

After disabling, restart Outlook app, and the Outbox folder should no longer be visible.

Obviously if you prefer the ability to access your emails/calendar offline, this may not be worth it for you, but for me this seems to have fixed the issue.

We have the same issue. I'll add a few more observations: Closing Outlook and Re-Opening Outlook resolves the issue until I send more e-mails. 2) Eventually they will be purged from the Outbox but that comes hours later. The e-mail has definitely been sent, since I get replies to it. They just sit in the Outbox marked as 'Queued'. Annoying. I can resolve it by closing Outlook and ReOpening. And that probably is the recommended resolution for Microsoft. But it's unacceptable for us.

Frustrated..

only fix i found was to remove the email account and re-add it and then the outbox message disappeared

settings > accounts > email accounts > select Manage button next to account in question > Remove

and then re-add it

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