enabling 128-bit encryption on a TLS enabled Send Connector

[Candace]

I used the following nine steps (see below) to create a specific Send
Connector with TLS enabled. However my customer who is requiring 128-bit TLS
email communications says that their test with my server failed because
"encryption too weak 0 less than 128". What changes do I need to make to may
TLS setup so that the encryption level used is 128-bit for the send connector
that I have applied these settings to?

Here are the steps I used to create a sender connector on the Exchange 2007
hub transport server:

1. On the Hub Transport server, open Exchange Management Console.
2. Navigate to Organization Configuration -> Hub Transport.
3. In the Result pane, right-click to New Send Connector.
4. Type the name, and choose Custom, then click Next.
5. Click Add to add the test domains in Address, and set Cost, then click
Next.
6. Click Next; ensure the hub transport server is listed as 'Source Server',
then click Next.
7. Click New and Finish to complete.
8. Open Exchange Management Shell, and run the command:
Set-SendConnector -Identity "<Name of the Send Connector>" -RequireTLS $true
9. Restart Exchange Transport service in 'services.msc'.