Getting all emails in an Outlook mailbox

Does anyone have insight into how the newest/latest/greatest Microsoft Intgegration for Office 365/Outlook (2.4.3) actually retrieves messages with the “For Each Email” activity?

First, I am aware of the “275 item” limitation that occurs if you use any filters within the activity (365 for each email stopping).

Beyond that problem, my issue is that the activity randomly sees or doesn’t see a lot of emails in many user’s email mailboxes, especially “old” email. These are messages that are visible in Desktop Outlook via the “more on the server” link and searchable in the user’s mailbox in browser Outlook.

For example, a user has a folder with several subfolders and hundreds of emails dating back several years. “For Each Email” found 29 messages in the entire folder/subfolder structure. The rest were ignored.

In my own email, I experimented with changing my Desktop Outlook Account Settings to show several years (default is one year for our config). Once I did this, O365 Outlook activities also “saw” the emails.

So the questions are:

  1. What is the actual Microsoft Graph query that For Each Email is doing?
  2. What has to be true of an email for it to be found by For Each Email?
  3. What is the relationship of Desktop Outlook settings and server/cloud-level email storage with respect to how Microsoft Graph sees the emails.

Any insights appreciated!