Managing personal Outlook.com account settings, security, and privacy
@KISHAN HARATHI said
my e-mails in "Inbox" and "Sent Items" are available only from 2020. I remeeeember most of them were not deleted by me. How to retrieve from e-mails from the beginning? I have also tried through outlook.com web but no result
Microsoft never deletes emails from your Inbox and Sent Items (unless you run out of storage).
https://support.microsoft.com/en-us/onedrive/microsoft-storage-quotas
Microsoft does not maintain any backups of your emails. If you can not find them in any folder using Outlook Web, then I am sorry, but they are gone.