If the user enables an auto-expanding feature, then additional storage will be added when the archive mailbox touches 100 GB.
To receive new emails, you should delete the non-critical emails from your inbox.
In such a condition, you will not be able to send any new message to any other user.
Any change in the document or spreadsheet is updated instantly and with the help of versioning, you can access the previous versions of the same file also. An Office 365 account has many benefits like all the account’s data and its details are fully secured and accessible globally.