So the different types of commands when trying to privately communicate with someone are as follows
To speak with someone the same way the say
command works, uses this command:
whisper [Name of character] = [Message]
message [Name of character] = [Message]
mail [Name of character] = [Message]
This will send a message to a player just like the say
command would, by having your character directly talk or message with the target.
To have your character perform an action the same way the pose
command would use this one
whisper [Name of character] =: [Action]
message [Name of character] =: [Action]
mail [Name of character] =: [Action]
Finally, if you would like to speak with them in an ooc
manner, use this one
whisper [Name of character] => [Message]
message [Name of character] => [Message]
mail [Name of character] => [Message]
Basically, just make sure to add those symbols after the equal sign and you should be good to go!