24 terms, defined in one sentence first
iMessage and business texting glossary
Every term you will meet while evaluating outbound messaging. Defined in one sentence first, then fully explained.
What vocabulary do you need to evaluate business texting?
Four clusters cover everything a buyer meets. Channel terms: iMessage, SMS, MMS and RCS are different routes. The blue or green bubble shows which route a message took.
Compliance terms split into two families often conflated: A2P 10DLC is carrier plumbing (registration, trust scores, per-message fees). TCPA is federal law (consent, opt-outs, revocation). A channel can sit outside registration and stay inside the law.
Deliverability terms (sender reputation, filtering, pacing, hygiene, suppression) decide whether messages arrive. Operational terms cover dedicated lines, fallback, availability checking, delivery states and opt-out handling. Start with A2P 10DLC and blue bubbles if new.
All terms, A to Z
- A2P 10DLC
- A2P 10DLC is the US carrier registration system that every business must complete before sending application-to-person text messages from a standard 10-digit phone number.
- Blue bubble
- A blue bubble is the visual indicator that a message was sent as an iMessage between Apple devices, rather than as a green-bubble SMS through a carrier.
- Carrier filtering
- Carrier filtering is the automated screening mobile networks apply to business text messages, blocking or throttling traffic they judge to be spam.
- Cold outreach
- Cold outreach is contacting a prospect who has no prior relationship with your business and has not requested contact.
- Conversational messaging
- Conversational messaging is two-way business texting designed to produce replies and dialogue, rather than one-way broadcast announcements.
- CRM trigger
- A CRM trigger is an event in your customer database, such as a stage change or form submission, that automatically starts an outreach action.
- Dedicated line
- A dedicated line is a phone number assigned exclusively to one business for its messaging, rather than shared across multiple senders.
- Deliverability
- Deliverability is the share of your sent messages that actually reach recipients' devices, as opposed to being filtered, blocked, or silently dropped.
- Green bubble
- A green bubble means the message was delivered as SMS or MMS through a mobile carrier rather than as an iMessage.
- iMessage availability check
- An iMessage availability check is a lookup that determines whether a phone number or email address can receive iMessages before you send to it.
- iMessage marketing
- iMessage marketing is the practice of running business outreach campaigns over Apple's iMessage service, so messages arrive as blue bubbles rather than carrier SMS.
- MCP server
- An MCP server is a service that exposes a product's capabilities to AI assistants through the Model Context Protocol, letting an assistant use that product directly.
- Message fallback
- Message fallback is the automatic process of re-sending a message over a lower tier channel when the preferred channel is unavailable for that recipient.
- Opt-out
- An opt-out is a recipient's request to stop receiving messages, which must be honored promptly and permanently across your sending systems.
- Pipeline revival
- Pipeline revival is the practice of re-engaging old leads that went quiet, rather than sourcing entirely new prospects.
- RCS
- RCS (Rich Communication Services) is the modern carrier messaging standard that brings read receipts, typing indicators, and high-quality media to non-iMessage devices.
- Sender reputation
- Sender reputation is the accumulated trust score a phone number or sending identity earns based on how recipients and networks respond to its messages.
- Show rate
- Show rate is the percentage of booked meetings where the prospect actually attends.
- SMS segment
- An SMS segment is a 160-character unit of billing; longer messages are split into multiple segments and billed for each one.
- Speed to lead
- Speed to lead is the elapsed time between a prospect raising their hand and your first meaningful contact attempt reaching them.
- TCPA
- The Telephone Consumer Protection Act is the US federal law governing automated calls and texts to consumers, including consent requirements and opt-out handling.
- The Campaign Registry (TCR)
- The Campaign Registry is the central database where US businesses register their brand and messaging campaigns before carriers will deliver their A2P SMS traffic.
- Throughput
- Throughput is the number of messages a sending number is permitted to deliver in a given period.
- Webhook
- A webhook is an automated HTTP callback that notifies your system in real time when an event happens, such as an inbound reply or a delivery status change.
Frequently asked questions
What do the blue and green bubbles actually mean?
Bubble color shows the channel. Blue is iMessage (Apple's internet service, with read receipts and typing indicators). Green is SMS or RCS (carrier network). Buyers read the color before reading the message.
What is A2P 10DLC in one sentence?
US carrier registration for SMS from standard 10-digit numbers: register brand and campaign, get a trust score, pay per-message fees. iMessage sits outside the system entirely.
What does deliverability mean in business texting?
The share of sent messages that reach a phone's inbox instead of being filtered or dropped. It's driven by sender reputation, sending patterns, list quality and the route. It decides whether a campaign's math works.
What counts as consent under TCPA?
Marketing texts need prior express written consent; other categories carry lighter standards. Recipients can revoke by any reasonable means, and senders must honor it within 10 business days. TCPA entries cover the distinctions; not legal advice.
How is RCS different from SMS and iMessage?
RCS is the carrier upgrade to SMS, with typing indicators and read receipts. iMessage is Apple's internet service, the only one that renders blue. Blue Reacher's fallback tries iMessage, then RCS, then SMS.
Why does sender reputation matter more than any single campaign?
It compounds: carriers score pacing, reply rates, complaints and hygiene over time. Damaged reputation follows the number, suppressing future campaigns. Serious platforms pace sending to stay conversational instead of blasting.