Error 'Insufficient Privileges' on My Email to Salesforce Settings Page

This error shows due to the lack of 'Email Administration' permission on the profile level. We can enable this permission through the developer console using the following steps:
 

1. Click the gear icon
2. Click Developer Console
3. Click Query Editor tab
4. Paste the query SELECT ID, PermissionsEmailAdministration FROM Profile WHERE Id = '<profile ID>'
5. Click Execute
6. The query result is rendered as "False"
7. Double-click the result and select the check box.
8. Click Save Rows
9. The result updates to "True"

When the 'Email Administration' permission on the specific profile is enabled, users can now access the 'My Email to Salesforce' Settings. These troubleshooting steps can also be applied when 'My Email Settings' is missing on the personal settings page.