How to evaluate iMessage, SMS and RCS for customer conversations
iMessage reaches iPhones with typing, read receipts and reactions; RCS reaches eligible Android phones; SMS reaches everyone. Choose by recipient capability and measure your own outcomes.
SMS · short code 62884
Your order has shipped. Reply STOP to opt out.
iMessage · your line
hey! your order's out for delivery 📦
Read 9:41 AM
Begin with reach and interaction
iMessage reaches iPhone users with typing indicators, read receipts and reactions. RCS brings similar features to Android phones on eligible lines and carriers. SMS reaches every phone but has no read receipts.
A good setup uses all three and routes each message to the best channel the recipient supports.
SMS can support two-way customer conversations as well as notifications. iMessage and RCS can provide richer interaction where sender and recipient capabilities support it. Neither blue nor green guarantees that a customer trusts or answers a message.
Compare recipients, supported countries, media, threading and sender identity. Test the features you need on the proposed production line rather than assuming that every client feature is exposed through the API.
Measure evidence separately
Acceptance is not delivery. Delivery and read events depend on the channel, line, recipient, and available receipts. SMS does not provide read receipts.
Instrument accepted sends, confirmed delivery, inbound replies, handoff and the business outcome you care about, and compare channels on comparable cohorts over the same window.
Understand routing conditions
RCS requires a supported dedicated line, carrier enablement, and a compatible recipient. Sending currently supports one plain-text message to an E.164 phone number.
Auto routing selects an available channel for the sending line and recipient, moving to another channel only after a confirmed pre-send rejection. RCS fallback supports plain text. An uncertain result does not trigger another send. An explicit channel never falls back.
Build a conversation, then evaluate it
Use a signed webhook receiver and durable event IDs. Resolve the receiving line to a tenant, store conversation state and pause automation when a human takes over. Maintain opt-out handling across both automatic and manual sending tools.
Payment requests use checkout links only when the global Payments product and workspace payments are enabled and merchant requirements are met. Native in-thread Apple Pay is coming soon; checkout links are not native Apple Pay in Messages.