Issues with sending emails from the Shared Mailbox in Outlook Desktop

Encountering an error when trying to send emails from the desktop client (Error: 0x80070005-0x000004dc-0x00000524).

Troubleshooting Steps:

Verify Permissions:
- We need to ensure that the correct permissions are set for the shared mailbox (e.g., Send As or Send on Behalf).
- Navigate to the Microsoft 365 Admin Center:
  - Go to Groups > Shared Mailboxes.
  - Select the shared mailbox.
  - Go to Delegation and confirm that the necessary permissions are assigned.
Repair or Recreate the Outlook Profile:
- Sometimes, Outlook profiles can cause issues. I suggest either repairing or creating a new profile:
  - Go to File > Account Settings > Account Settings.
  - Select the account and click Repair.
  - Alternatively, create a new profile via Control Panel > Mail > Show Profiles and re-add the shared mailbox.
Disable Cached Exchange Mode:
- Disabling Cached Exchange Mode for shared mailboxes can help sync issues:
  - In Outlook, go to File > Account Settings > Account Settings.
  - Select your account, click Change, and uncheck Use Cached Exchange Mode.
  - Restart Outlook and try sending an email again.
Check Outlook Client Version:
- Ensure your Outlook client is up to date:
  - In Outlook, go to File > Office Account > Update Options and select Update Now.