Chinese hackers targeted State and Commerce Department officials’ email accounts before Secretary of State Antony Blinken’s Beijing visit. Microsoft reported 25 organizations were targeted. US officials claim no sensitive info was accessed, but can we really be sure? Emails will contain non-public information, even if it's not classified information. #cybersecurity #hacking #China #US #politics

https://ground.news/article/chinese-hackers-breach-email-of-commerce-secretary-raimondo-and-state-department-officials_c7113e

Chinese hackers breach email of Commerce Secretary Raimondo and State Department officials

Chinese intelligence hacked into Microsoft email accounts belonging to two dozen government agencies, including the State Department, in the U.S. and Western Europe in a “significant” breach, according to Microsoft.

Ground News
@FlippingBinary

On the Internet-connected O365 systems, only up to
CUI is allowed. So, individual emails/threads would notionally be "not sensitive". However, with a wide enough net, you could expect to attain a "classified through aggregation" status.
Controlled Unclassified Information (CUI)

Everything you need to know about Controlled Unclassified Information.  The page is broken down into the following sections:

Federal Trade Commission