Question: In an SMS setup as per 3GPP specifications, what is a permissible action for an email <-> SMS gateway when handling messages to enhance user presentation?
Option 1: Inserting additional non-space characters in the MT (Mobile Terminated) message
Option 2: Adding extra spaces in the MT message for better user display
Option 3: Removing existing spaces from the MO (Mobile Originated) message for efficiency
Option 4: Rejecting MO messages with additional spaces inserted by the user
Explanation: According to the specifications, an email <-> SMS gateway is allowed to insert additional spaces in the MT message to improve how the message is presented to the end-user. This action enhances readability without altering the message's content, aligning with the goal of effective user presentation.