IBM TS4300 1.1.0.1 through 1.7.1.1 could allow an authenticated user to cause a denial of service in the email service due to improper control of interaction frequency.
For the 1.7.1.1, upgrade to version 1.7.2.0 or later, available from IBM Fix Central http://www-933.ibm.com/support/fixcentral/ .
All future releases will include the fix for this vulnerability.