Power Automate Flow: Email Attachment to SharePoint Folder

Question

I have created a flow that is intended to capture the attachments from emails sent to a Shared Mailbox and create them in a SharePoint Folder. Below is the Flow and the error I am getting. Please assist and Thank You in advance.

Answer 1

Hi @MJ McSheehy,

Thank you for the detailed screenshot.

That error, "The specified object was not found in the store., Default folder Inbox not found," means Power Automate cannot resolve the Inbox folder of the shared mailbox using the current connection. The most common causes are:

1. The connection account does not have proper access to the shared mailbox
2. The shared mailbox has never been initialized for that account
3. The mailbox address is resolved, but the folder ID (Inbox) cannot be found
4. A stale or broken Outlook connection is being used in the trigger

You should try the following steps to see if it helps your issue:

1/ The account used in the Outlook connection must have:

• Full Access to the shared mailbox
• (Send As is not required for reading emails)

After permissions are granted, allow time for Exchange Online to propagate them (this is explicitly required for this trigger to work).

2/ Initialize the shared mailbox:

Even with correct permissions, Power Automate will fail until the mailbox is opened at least once by the same account used in the flow connection. Please try to:

1. Sign in to Outlook on the web with the account used by the flow
2. Click your profile picture > Open another mailbox
3. Enter the shared mailbox address and open it
4. Close Outlook and re-run the flow

This forces Exchange to initialize the default folders for that user.

3/ Recreate or refresh the Outlook connection

If the error persists, please do the following steps to resolve stale connections:

• Go to Power Automate > Data > Connections
• Delete the existing Office 365 Outlook connection
• Recreate it using the correct account
• Re-select this new connection in the trigger

4/ Manually type the shared mailbox address

In the trigger:

• Do not use dynamic content or environment variables
• Manually type the full SMTP address (e.g. ******@domain.com)
• Let Power Automate resolve it automatically

Incorrect resolution of the mailbox address can cause the Inbox lookup to fail even though the mailbox exists.

5/ Save As > copy the flow:

If everything looks correct and it still fails:

1. Open the flow
2. Select Save As
3. Create a copy and run the copied version

This refreshes internal references and “object not found” errors caused by corrupted metadata.

However, in case you require more in-depth guidance or support for troubleshooting, I’d recommend posting your query in the Microsoft Power Automate Community. This is a dedicated channel for Power Apps discussions. The reason I suggest posting a new topic there is that in the general Q&A Forum, resources and expertise on Power Automate are limited. In the Microsoft Power Platform Community Forum, you’ll find the most qualified group of respondents, and other partners who regularly read the forums can share their knowledge or learn from your interaction. 

I hope this information is helpful. Should you have any further questions or need additional assistance, feel free to reach out.    

In the meantime, if you see my replies bring helpful information, please kindly accept it as an answer and vote it up by your original account, which raised this question. Once marked, it will automatically pin to top. As other users will also search information in this community, your valuable vote up will definitely also help other users who have similar queries easily to find the correct channel and useful information more quickly.   

Thank you again for your understanding and cooperation. 

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Answer 2

The error occurs in the trigger When a new email arrives in a shared mailbox (V2) before any of the attachment/SharePoint steps run. The message indicates that the trigger cannot find the default Inbox folder for the mailbox it is trying to use.

To fix the flow, configure the shared mailbox correctly in the trigger and ensure attachments are included:

1. Edit the flow and open the trigger When a new email arrives in a shared mailbox (V2).
2. In the trigger card, make sure the Mailbox address (or equivalent field) is explicitly set to the correct shared mailbox address. If it is blank or points to a mailbox that no longer exists, the trigger will fail with the “Default folder Inbox not found” error.
3. Select Show advanced options on the trigger.
4. Set the attachment-related options so the trigger can see and pass attachment content:
   • Set Only with attachments (hasAttachments) to Yes if the flow should trigger only when there are attachments.
   • Set Include attachments (includeAttachments) to Yes so that the attachment content bytes are available to downstream actions like Create file in SharePoint. If this is left as No, attachment content will be null and any file-creation step that uses it can fail with a 400 Bad Request or similar error.
5. Save the flow and send a test email with an attachment to the shared mailbox to confirm that the trigger now runs and the SharePoint Create file action receives the attachment content.

If the shared mailbox is on a server or plan where the Outlook REST API is not supported, the trigger can also fail. In that case, verify that the mailbox is a valid Microsoft 365 mailbox on a supported plan as described in the email troubleshooting guidance.

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References:

• Issues triggering emails with attachments from shared mailbox
• Troubleshoot common issues with email in flows
• Microsoft SharePoint Connector in Power Automate