Short description of the flow before I outline the issue I'm experiencing: When a new email arrives in a shared mailbox (V2) - The flow triggers when an email is dropped into a specific folder within the shared mailbox within Outlook. Once triggered, the flow passes the sender info, email title, body of the message, any attachments, and a few other pieces of data to a new entry in a Microsoft List where it can be processed, and cataloged with additional data fields for future reporting.
The flow shows as working fine on the run history. I don't see any failures or instances of the flow running for an abnormally long duration. However, the users leveraging the flow will randomly encounter instances where the flow just misses an email that is placed in the folder it's set to trigger off of.
I've never encountered this with any other flow that triggers upon the arrival of a new email. The key difference here is that the users are manually moving emails to the folder the trigger is pointed to, rather than the emails just directly arriving within that folder. But as far as I can tell there's no pattern or similarity in the emails that fail to trigger the flow.
I've explored whether this was caused by some sort of synchronization lag with the Outlook desktop client to the degree that the flow would somehow miss the change in folder, but the same issue has also occurred when users attempt via the Outlook web app.
Any thoughts on what would cause the trigger to not fire?
You have to rewrite the flow. The trigger "When a new email arrives in a shared mailbox (V2)" works reliably only for emails delivered (not copied, not moved) to Inbox. So I recommend you to create a scheduled flow that will scan appropriate folders of a shared mailbox and handle the messages.