Microsoft
Microsoft
Do you have proof that this is true when signed in with a Business/Enterprise account?
Yes. In the New Outlook signed with a Business/Enterprise account, when you add an email account for an external provider, you need to send your credentials, username and password to Microsoft. Yo need to trust in Microsoft. You can't connect directly to your external email provider (POP3, IMAP, SMTP, etc.) to send /recieve emails like any other email client. It is Microsoft, which has your access passwords, and not you, that receives emails from third-party providers on Microsoft servers and then sends them to you. When you send email through an external account, you are sending it to Microsoft servers, which will then take care of sending it through your external account because it has your passwords for that account. All of this is spying. If not, why not connect directly to the external email (POP3, IMAP, SMTP, etc.) providers like any other email client? What is Microsoft doing with emails from external accounts stored on its servers?
