Product: Programmable SMS
Twilio queues messages based on the sending rate of a sender or an account. For example a US long code number can send one message segment per second, and a short code may send over 100 message segments per second.
Messages can only be queued for 4 hours and then they automatically fail. This queue length limit can be reduced by setting a lower Validity Period within your Messaging Service settings or in your API requests to send messages.
You can monitor the length on your queue via the Queue Insights dashboard.
For more information please view this FAQ.
- You tried to send too many messages too quickly and your message queue overflowed.
- You tried sending all your messages from a single Sender with an insufficient send rate limit (Message Segments per Second) for that volume, and you need additional throughput to handle the volume.
- There are Messages Per Second (MPS) limits applied for your Senders, Messaging Services, and Accounts that you may be encountering.
- Recommended Try using a Messaging Service with multiple senders and it will load balance for you.
- Try adding more senders into your Messaging Service.
- If you are messaging in the US or Canada, talk to Twilio Sales about getting a Toll Free or Short Code number that allows you to send more messages per second.
- Try sending your message again after waiting for some time.
- If you have set a lower Validity Period than the default and maximum value of 14400 seconds (4 hours), try setting a higher Validity Period for your messages.