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From what I've understood by reading message headers and settings in Outlook, mails sent between Outlook on my PC and the Exchange cloud service are encrypted with TLS 1.2. Messages moving within the cloud between domains are also of course secured in the same way.
Is this more or less secure than transferring files to a server through an HTTPS connection? And how about when, let's say, mails go from Exchange to Google's cloud. Do they also transfer over TLS?