Hello. I have been trying to send a message to an extension, after dialing it, by pressing the Message button when the extension is ringing, but I get the "Not allowed" message. Testing this using a different extension works and the dialed extension successfully flashes orange. After looking around I found out that the extension, which successfully sent the message, has a different Class of Service (COS) to the initial extension I used that did not work. I compared these two COS forms and it turns out that they have the same settings under Class of Service Options -> Advanced -> Message Waiting:
Message Waiting Yes
Message Waiting - Disable Ringing Lamp Notification No
Message Waiting Audible Tone Notification No
Message Waiting Deactivate On Off-Hook No
Message Waiting Inquire No
Message Waiting Ringing Start Time Hour
Message Waiting Ringing Start Time Minute
Message Waiting Ringing Stop Time Hour
Message Waiting Ringing Stop Time Minute
Multiline Set Voice Mail Callback Message Erasure Allowed Yes
ONS CLASS/CLIP: Message Waiting Activate/Deactivate No
Are there any other settings (in addition to the above), under the Class of Service Options form, which I need to change to allow the extension to send a message to an extension after pressing the Message button?