Update (April 2023): For Microsoft 365 operated by 21Vianet, TLS1.0 and TLS1.1 for SMTP AUTH will no longer be supported after June 30, 2023. We will be disabling TLS 1.0 and TLS 1.1 usage with SMTP,...
Updated Apr 13, 2023
Version 5.0
Blog Post
3 MIN READ
New opt-in endpoint available for SMTP AUTH clients still needing legacy TLS
If TLS versions are now to be hardcoded how about MS update their articles that advise against it ?
Microsoft recommendations are specifically against hard coding TLS versions in projects in this article
https://docs.microsoft.com/en-us/dotnet/framework/network-programming/tls ..
"To ensure .NET Framework applications remain secure, the TLS version should not be hardcoded. .NET Framework applications should use the TLS version the operating system (OS) supports."
And then.
"Do not specify the TLS version. Configure your code to let the OS decide on the TLS version."
And then
"Perform a thorough code audit to verify you're not specifying a TLS or SSL version."
Following this advise would have lead any developer not specifying the TLS version to have significant problems with the change initiated above hidden in messaging no one would have got to finding