Use text when immediacy and conversation matter.
SMS is not a replacement for every email, phone call or support channel. It works best when a short, timely message can help someone take the next step or reply quickly.
Strategy guides
A simple channel rule
Use SMS for concise, time-sensitive or conversational steps. Use email when the reader needs detail, attachments, longer explanation or a searchable record. Use phone when nuance, urgency or trust is better served by a live conversation. A mature system can move between all three.