# What is a message queue in messaging?

> A message queue holds submitted messages until they can be sent, smoothing bursts and respecting throughput limits. When you submit faster than the route allows, the platform queues the overflow and releases it at the permitted rate, so a spike does not overwhelm the operator or breach rate limits. Queue behaviour affects how quickly a large or bursty send actually goes out.

- Canonical URL: https://www.broadnet.me/answers/what-is-a-message-queue
- Language: en
- Last reviewed: 2026-07-22
- Publisher: BroadNet (https://www.broadnet.me)

## Why queues exist

Operator throughput is finite, so a platform buffers messages and meters them out at the allowed rate — protecting delivery and honouring rate limits during bursts like an OTP spike. See /answers/what-is-rate-limiting-sms and /answers/what-is-tps.

## What it means for timing

If you submit a large campaign instantly, the queue releases it over time at your throughput ceiling — so provision enough capacity, or schedule, for time-sensitive sends. See /answers/how-to-scale-sms-throughput.

## Validity and expiry

Queued messages carry a validity period; if they cannot be delivered before it expires, they fail. Monitor queue depth and delivery receipts for time-critical traffic. See /answers/what-is-validity-period and /answers/what-is-dlr.

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [What is rate limiting in SMS?](https://www.broadnet.me/answers/what-is-rate-limiting-sms)
- [What is TPS (Transactions Per Second)?](https://www.broadnet.me/answers/what-is-tps)
- [How do I scale SMS throughput?](https://www.broadnet.me/answers/how-to-scale-sms-throughput)
- [What is the SMS validity period?](https://www.broadnet.me/answers/what-is-validity-period)
- [SMS API](https://www.broadnet.me/products/sms-api)