使用 iOS 版 Outlook 進行個人電子郵件與行事曆管理
Hi,
I can assure you it is normal.
The sender may have used Recall This Message and resent it, which can sometimes result in the original disappearing and a new copy arriving. Another possiblity is that the mail server or a rule re-delivered the message. This can happen if the sender's mail system retried delivery (e.g., they didn't get a delivery confirmation the first time).
Nothing to worry about, since I think the former was the actual cause.
I hope this information helps. If you have any more questions, don't hesitate to reach out.
Otherwise, please take a moment to rate the answer. Wishing you good luck!