Cause: The e-mail address and password were not typed correctly.
Solution: Retype your e-mail address and password.
Passwords are case-sensitive.
If you do not know your corporate e-mail address and password, see your system administrator.
Cause: The firewall that is built into Mac OS X is blocking Communicator.
Solution: Confirm that your firewall settings are not blocking incoming connections for Communicator.
A symptom of this problem is that Communicator times out while you are trying to sign in.
On the Apple menu, click System Preferences.
Under Personal, click Security, and then click the Firewall tab.
If the firewall has blocked incoming Communicator connections , see your network administrator.
Cause: Your corporate network connection is not using the network protocol you expect.
Solution: Manually configure your network settings.
When automatic configuration is selected, Communicator uses the TLS protocol. If TLS is unavailable, then Communicator uses the TCP protocol.
To manually configure your network settings:
On the Communicator menu, click Preferences.
Click Account , and then under My Network Settings, click Manually configure settings.
Enter the server name or IP address.
Click either TCP or TLS.
Cause: Communicator cannot retrieve your user ID and password from the network.
Solution: Enter your e-mail address, user ID, and password manually.
If the Use my network ID and password check box is selected in the sign-in window, Communicator uses an authentication method called Kerberos protocol to locate your network ID and password. If this is unsuccessful, try entering your user ID and password manually.
In the sign-in window, clear the Use my network ID and password check box.
Type your e-mail address, user ID, and password.