Exchange on-premises and Exchange online is supported TLS 1.2, and suggested to disable TLS 1.0 and TLS 1.1. For more detailed information, you could have a look about those article below.
- Exchange Server TLS guidance, part 1: Getting Ready for TLS 1.2
- How Exchange Online uses TLS between Exchange Online customers
- An Update on Office 365 Requiring TLS 1.2
About 3DES, it is suggested disable RC4 to use 3DES.
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