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iMessage isn’t filtered by carriers the way SMS/MMS is. There’s no keyword filtering, content scanning, or per-segment fees to worry about. Instead, Apple protects the network by watching for sending patterns that look automated or spammy, and can flag or restrict a number that trips those signals. There’s no carrier in the middle to appeal to, so staying in good standing with Apple’s detection systems matters even more than it does for SMS. To keep your messages landing as blue bubbles, and your number in good health, follow these guidelines.
Rate limits, link preview quirks, and a full list of what can get a number flagged live on the separate Caveats & Limits page.

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Pick a sending strategy first

Whether you or the customer sends the first message in a conversation is the single biggest factor in how risky your sending looks to Apple. Most products use both approaches for different situations:

Inbound-first

The customer messages you first.

Outbound-first

You message someone first.

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Personalize every message

Never send identical content

Sending the exact same text to many recipients is one of the clearest spam signals there is. Vary greetings, names, and context per recipient rather than reusing one template verbatim.

Reference something specific

Mention the recipient’s name, order, appointment, or last interaction. Generic blasts undercut the personal feel that makes iMessage effective in the first place.

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Send like a human, not a script

Avoid fixed intervals

A message sent every exact 10 seconds is an obvious automation fingerprint. Add randomized delays between sends instead of a fixed cadence.

Cluster and pause

Humans send a few messages, pause, then come back later. Avoid blasting an entire list in one continuous run. Break volume into smaller bursts with gaps in between.

Respect the clock

Send during normal daytime hours in the recipient’s timezone. iMessage notifications are immediate and prominent, so late-night messages are more likely to be flagged or reported.

Vary your daily volume

Sending exactly the same number of messages every single day is another pattern detection systems look for. Natural variation looks more human than a constant, mechanical rate.

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Ramp up gradually

New or newly-leased numbers should ramp volume up gradually rather than sending at full throughput on day one. A sudden spike in sending from a number with little prior activity is a strong risk signal to Apple. If you’re expecting to send meaningfully higher volume, reach out on Discord or email help@contiguity.support so we can help you scale safely. Also consider leasing multiple numbers to distribute volume rather than pushing it all through one line. iMessage is exempt from A2P 10DLC, carrier vetting, and mandatory opt-out language. See our compliance overview. That doesn’t mean consent stops mattering: you’re still responsible for complying with applicable laws in your jurisdiction (e.g. TCPA, GDPR, CASL). If a recipient asks to stop, stop.

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Use rich features, not just plain text

Part of what makes iMessage worth using over SMS is the feature set. Leaning on it makes your messages feel like they’re coming from an attentive person, not a script.

Use reactions

A tapback on the customer’s message acknowledges it instantly, and looks infinitely more human.

See docs >

Mark messages as read

Marking a conversation as read as soon as you’ve seen it (or your system has processed it) matches how a real person uses iMessage.

Show typing indicators

Start a typing indicator before your reply lands, especially if there’s any processing delay (an AI agent thinking, a lookup running).

See docs >
Still have questions? Join our Discord community or email us at help@contiguity.support.