Not really sure when it started but i am currently missing a huge part of my emails.. I have been looking for ways to recover, but so far I've found nothing that has helped..

A little history: I am viewing my emails on a Mac Mail app and on iphone mail app. i do have it set to POP enabled and Don't let devices or apps delete messages from Outlook. So if I delete anything it goes to that POP folder instead..but the issue is not with my deleted messages.. the issues is with the messages that I have left in the inbox..
where are they? and how can i get them back?