You can access your voicemail from your Voip phone, or, from any other telephone. To access your voicemail by telephone:

From a touch-tone phone, dial your phone number
If you hear your greeting
Press the star (*) key
Press the 1 key for Voicemail
Enter your extension
Enter your pin code
Once you have successfully entered your passcode, you are within your voicemail system. Please follow the operator instructions to access your messages, change your greetings, or modify other voicemail options.