---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21611#article
headline: "21611: This 'From' number has exceeded the maximum number of queued messages"
url: https://www.twilio.com/docs/api/errors/21611
inLanguage: en
dateModified: 2026-06-08T11:38:30.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21611: This 'From' number has exceeded the maximum number of queued messages

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio returns 21611 when you try to create another outbound message for a `From` sender whose queue is already full. Twilio queues outbound messages according to the throughput available to a sender or account, and a queue can hold up to 10 hours of message segments. If you send with a Messaging Service, sender pool overload can instead appear after message creation as error 30001.

### Possible causes

* Your application is submitting messages for one `From` sender faster than Twilio can dequeue them at that sender's available throughput. ([help.twilio.com](https://help.twilio.com/hc/en-us/articles/115002943027-Understanding-Twilio-Rate-Limits-and-Message-Queues))
* The queued volume for that sender has grown beyond the maximum queue window, which is up to 10 hours of message segments. ([help.twilio.com](https://help.twilio.com/hc/en-us/articles/115002943027-Understanding-Twilio-Rate-Limits-and-Message-Queues))
* You set a lower Validity Period on the message request or Messaging Service, which reduces how long messages can remain queued before they fail.

### Possible solutions

* Reduce the rate at which your application submits messages for that sender so the queue can drain.
* Use a Messaging Service when it fits your use case so Twilio can distribute traffic across an appropriate sender pool.
* Review the Validity Period on the message request or Messaging Service. If you set it below 36,000 seconds, increase it as needed up to the 10 hour maximum.
* Monitor queue time, delivery failures, and backlog trends in Messaging Insights or Messaging Logs so you can detect congestion before new requests start failing.

#### Additional resources

* [Understanding Twilio Rate Limits and Message Queues](https://help.twilio.com/hc/en-us/articles/115002943027-Understanding-Twilio-Rate-Limits-and-Message-Queues)
* [Messaging Services](/docs/messaging/services)
* [Messaging Insights Dashboards](/docs/messaging/features/messaging-insights/dashboards)