How can you troubleshoot Send Outlook Desktop Mail Message when emails remain queued in Outbox and never appear in Sent Items?
Issue Description
Emails sent through Send Outlook Desktop Mail Message can remain queued in the Outlook Outbox and never appear in Sent Items.
When this happens, the automation can appear to complete the send step, but Outlook does not finish submitting the message.
This pattern is more commonly tied to Outlook desktop state on the machine than to a direct failure in the UiPath activity itself.
Resolution
- Preferred path: migrate to Microsoft 365 / Office 365 mail activities
- Migrate the workflow from
Send Outlook Desktop Mail Messageto the Microsoft 365 / Office 365 mail activities. - Use the Send Mail documentation for the mail activity and the About the Microsoft 365 activity package guide for setup and package context.
- If authentication or connection setup is required, use the How to connect to Microsoft 365 activities guide.
- Migrate the workflow from
- Fallback path: remediate the Outlook desktop profile
- If migration is not possible, remove and recreate the Outlook profile on the affected VM.
- Re-add the mailbox cleanly and open Outlook manually once so the profile, mailbox, and local stores can initialize fully before running the automation again.
- Retry the automation and confirm that the message leaves Outbox and appears in Sent Items.
- If the issue continues, review Outlook event logs again and check for repeated mailbox-store reconciliation, stale local stores, or multi-mailbox profile inconsistencies on the affected machine.
Additional Information
- This issue can affect one mailbox or one VM, even when the broader automation is otherwise functioning.
- UiPath Outlook desktop activities depend on the local Outlook profile and desktop application state.
- Microsoft has introduced the new Outlook application as a replacement for the classic version. However, transitioning to the new Outlook breaks compatibility with UiPath's Outlook Desktop activities.(https://docs.uipath.com/activities/other/latest/productivity/new-outlook-impacts-outlook-desktop-activities)
- The Outlook Desktop activities don't work with the new Outlook, because it doesn't support COM add-ins.
- Outlook Desktop activities are in maintenance phase, and the newer Microsoft 365 Outlook activities are the forward-looking path. (https://docs.uipath.com/activities/other/latest/productivity/microsoft-outlook-desktop)
- See the Related Links field for the activity documentation referenced in this article.