Microsoft Office Upload Center - Microsoft Support
When you upload a file to a web server, Microsoft first saves that file locally to the Office Document Cache before it starts the upload, which means that you can save changes and immediately continue working even when you are offline or have a bad network connection.
Internet connectivity issues in M365 apps after a change to the IP ...
2022年8月8日 · Customers who had configured their firewalls to disallow IP addresses and ranges introduced in this Office update experienced connectivity issues. STATUS: FIXED. A fix has been deployed to correct the IP ranges (52.108.0.0/14) associated with the *.officeapps.live.com endpoint in the DF, SIP and US datacenters.
Save, back up, and recover a file in Microsoft Office
You can save a file to a folder on your hard disk drive, a network location, the cloud, a DVD, the desktop, or a flash drive. While you must identify the destination, if it is different than the default folder, the saving process is the same regardless of what destination you choose.