Recently, we were migrated from SP2013 to Sharepoint online, and we encountered a following problem:
We have "users" in AD which are basically just accounts for machines with no user interaction. As such, they don't have O365 account, e-mail etc. In old Sharepoint you could simply add them to site's permissions and it would work - now, even though they are added, SP still requires to login with e-mail account.
How can we make it so such an account has access to a folder in library to dump files in there?