Microsoft — Policy Change

Executive Summary

Security researchers discovered that the new Outlook for Windows app syncs IMAP and SMTP credentials and all emails to Microsoft's cloud servers when users add third-party email accounts like Gmail or Yahoo. German publications Heise and CT found that usernames and passwords were transmitted to Microsoft servers, and users could not use the new Outlook without cloud syncing. Proton Mail later called the new Outlook 'Microsoft's new data collection service.'