Cloud-based Message Recall in Exchange Online

Hi KevinShaughnessy , thanks for this article, it's substantially more helpful than the generic Microsoft Support pages.

I work at the IT support department at my company (not directly dealing with Outlook/Exchange issues though) and received a user prompt about this new recall method.

I've tried it myself and the results are a bit confusing: I was able to recall a mail, my colleague first saw it in his inbox and then after I recalled, it disappeared. However, the Recall Report indicates that this was unsuccessful. (Translation: Messages sent to external or on-premise recipients cannot be recalled)

Both of us have an Exchange profile of course.

Any idea why this is happening..?