Using older versions of Outlook for Mac for personal email and calendar
Hi DSW
I’m very sorry, especially because some of the missing emails have significant personal value.
Since the same Sent messages are missing on both the iPhone and Mac, first sign in directly at Outlook.com on a desktop browser. Search All folders for a known recipient or subject, then check Deleted Items, Archive, and Deleted Items > Recover items deleted from this folder. Microsoft normally keeps items in the recoverable area for up to 30 days after removal from Deleted Items.
Also review Settings > Mail > Rules for anything that may have moved or deleted messages. The account activity page only shows the previous 30 days, so activity appearing from August 8 does not by itself confirm what happened to the older messages.
Since you can't find the "Still need help" - you can still reach out to Microsoft Support by visiting Microsoft Support - Contact us
Finally, check whether an older Mac backup or local mail archive contains copies before changing or removing the account from any device.
Hope this helps, have a great day
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