I'm experiencing issues receiving TLS encrypted e-mail from a specific domain. We entered into an agreement to use a 256-bit cipher and apparently our Exchange 2007 server on Windows Server 2003 isn't offering that up as an option, thus everything is getting rejected for only offering 128-bit encryption.
Rather than have them change things on their end, I'd like to resolve it on ours. I found a hotfix that allows me to add 256-bit AES ciphers to the list of available ciphers. I installed the hotfix, but it did not resolve my issue.
After reading this article, I'm suspecting that our Exchange 2007 server's cipher order is offering up 128-bit encryption first, and then the remote server is RSET'ing the connection when we do so. I'd like to verify that our server is offering up the 256-bit encryption option first.
The Computer Configuration | Administrative Templates | Network | SSL Configuration Settings | SSL Cipher Suite Order key doesn't exist on my Windows Server 2003 Exchange box, so I can't modify it.
Does ANYONE have any clue about how to go about resolving this issue?