If you use Symantec Endpoint Protection to protect your IBM Lotus Sametime Gateway, the awareness for Yahoo users may not work for the time being, but AOL, Google and other Sametime communities are working correctly.
The reason for this may be the Symantec Intrusion Prevention which detects a “Telnet SoftEther VPN Software” coming from a .
As documented it might be a false positive.
This signature might false positive if any other application attempts SSL-style handshake on a Telnet port. Currently this behavior is thought to be restricted to SoftEther.
Disabling this rule in the SEP configuration will (temporarily) solve the issue, but of course, no guarantee that it is not an attack ;-)