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 parameter can be lowered by setting a different Validity Period within your Messaging Service settings.
You can monitor the length on your queue via the Queue Insights dashboard.
For more information please view this FAQ.
- You tried sending all your messages from a single Sender that had a send rate limit (Message Segments per Second) and need more senders 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. * 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. * Try setting a higher Validity Period for your messages (max is 14400 seconds, 4 hours)