I've seen that the same question has been asked and answered a lot, but the only solution I've seen seems to be when a Microsoft moderator steps in.

So like everyone else I upgraded to outlook a few months ago and have noticed now that the emails that I leave in my inbox are just automatically deleted, I've managed to save the important emails to folders, so that's fine. I check me emails via my iphone and web browser, the settings on my iphone do not have an auto delete feature; the settings in the web browser do not have a scheduled clean up for my inbox and I have the 'don't let devices or apps delete messages from outlook' feature checked.

Thanks is advance.