According to the link
http://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/118518-technote-esa-00.html
This has been fixed in TLSv1.2. You can change that if you use TLSv1.2
Please check the following for more information:
https://supportforums.cisco.com/discussion/12496926/tlsv11
Also you need to use anyconnect 4.x to connect using the new ciphers.