What is a Reply Response?
What is a Help Response?
System Responses (HELP, STOP, etc.)
What is a second time opt-in message?
STOP functionality
When a subscriber replies stop, does that remove them from all lists?
Will returning subscribers receive scheduled after opt-in messages sent to new subscribers?
How does STOP work when a subscriber is part of multiple lists?
What is a Stop Response?
What is an Already Subscribed Response?