Since TLS 1.0 protocol is not secure, it should be disabled worldwide, but applications using WinHTTP on Windows7 machines support TLS 1.0 only. As a result, Outlook throws the error "your server does not support the connection encryption type you have specified”.
There are two way to resolve it:
- Install the KB3140245 update, either via Windows Update — it’s available as an Optional Update, or obtain via the Microsoft Update Catalog.
- Download and run Easy Fix, as suggested by Microsoft. Available at https://support.microsoft.com/en-us/help/3140245/update-to-enable-tls-1.1-and-tls-1.2-as-a-default-secure-protocols-in-winhttp-in-windows. Or, if you like to edit the registry on your computer yourself (WARNING! This is dangerous if you don't know what you're doing!), create a DWORD value called DefaultSecureProtocols in both of the following locations and set its value to 0x00000A00:
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp
- HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp