Core Docs - Engagement - Configure SMS
Rock Version: v20.0
Last Modified: 2026-05-01 1:39 PM
You need to have a phone number before you can start sending and receiving texts. We recommend Twilio, and have a whole section for setting up Twilio. Even if you don’t have a phone number set up yet, it’s important to be familiar with the System Phone Number settings because they are referenced later in this article.
These settings can be accessed and maintained from Admin Tools > Settings > System Phone Numbers.
In addition to the Assigned to Person settings described above, you can apply security to each System Phone Number individually. Simply click the ti ti-lock icon when viewing the Phone Number to apply security for that number. Please note that the security does not transfer over to SMS Conversations, Communication Wizard and Simple Communication blocks.
You may also want to review the block settings for SMS Conversations to further refine how your numbers are used and who can see them.
Configure Twilio
Twilio is the leading SMS provider. Period. They not only provide the best service, but they are also one of the least expensive options available. Again, we don’t have a relationship with this organization, but we do know a good thing when we see it! Below are instructions on setting up this service for Rock.
SMS Pipeline
To set your number up for the SMS pipeline, use the 'Messaging Request URL'https://-YourServer-/Webhooks/TwilioSMS.ashx?SmsPipelineId=-YourPipelineId-
Make It Accessible
It's important that this address be accessible from the Internet so Twilio can access it.
4. Before you can actually use Twilio for real communications, you'll need to upgrade from the free trial.
5. From Rock navigate to Admin Tools > Settings > Communication Transports > Twilio. Enter in your Account SID and Auth Token and activate the transport. Click Save when done.
6. Next set the Twilio transport as the default transport for the SMS medium under Admin Tools > Settings > Communication Mediums > SMS.
7. Finally, add your Twilio phone number under Admin Tools > Settings > System Phone Numbers. You can add as many Twilio numbers here as you wish. Be sure that the phone number is in the Phone Number field and that it is in the format of “+15555555555” (or similar for international numbers). If you select an Assigned to Person, be sure the individual you select has a valid SMS phone number on their record.
Twilio Signature Validation
When you’re setting up your Twilio transport as described above (step 5), you’ll have an option to Enable Signature Validation. You’ll want to enable this if you're concerned that a system other than Twilio might try to send incoming SMS responses to your Rock server. Enabling this is a small step you can take to possibly avoid a lot of unwanted messages, and it helps keep your data secure.
In short, Signature Validation compares your Public Application Root (this is a Global Attribute in Rock) to the webhook that’s set in Twilio. If they match, the validation is successful, and the message will come through as usual. If they don’t match, then the message won’t reach Rock. There’s a bit more to it than that, and it gets a little technical, but we strongly recommend checking out the details on Twilio’s site so you can get this set up.
That's it! Now you’re set to send SMS messages from the Rock communications features.
Twilio's Impact Access Project for Non-Profit Organizations
Twilio offers a $500 kickstart credit to non-profit organizations. To learn more, visit www.twilio.org.
Twilio, Short Codes and MMS Messages
If you're using a Twilio short code, keep in mind that it doesn't automatically support MMS messages. You can add MMS capabilities for a one-time fee of $500. This is different than regular "long codes" (phone numbers) where MMS is usually automatically supported.
If you're not sure whether your account supports MMS messaging, check your Twilio Console. If you only see "Capabilities: SMS" and MMS is not listed, then it's likely you haven't purchased MMS for your short code.
To set your number up for the SMS pipeline in Twilio, set the A Message Comes In URL to:https://YourServer/Webhooks/TwilioSMS.ashx?SmsPipelineId=YourPipelineId
If you need multiple SMS Pipelines, you can link each one to your phone numbers by specifying the pipeline’s ID in the URL.
SMS Number Strategies
Now that you've seen how SMS replies are handled in Rock, let's touch briefly on strategies to implement this effectively in your organization.
SMS services like Twilio make it very inexpensive to rent phone numbers for SMS. (A number from Twilio runs only $1 per month.) Don't limit your organization to a single number if you need more than one. Think about getting a number for each department and/or heavy SMS user. It's also very easy to turn an SMS number on and off. You might grab a number for a large event and remove it after the event is over. You can also reuse a number internally by changing the Response Recipient as described above.
MMS Considerations
Standard MMS (aka, Multimedia Messaging Service) messages allow you to send images, slideshows, videos and audio clips as attachments. While this means you can do some creative things with your communications, there are some limitations to keep in mind.
The biggest limitation is that the recipient's phone may not support all multimedia files. So, while you may be able to send a short video, not all of your recipients may be able to view it.
Another thing to keep in mind is that some mobile carriers limit the file size of attachments being sent over their network. For example, Twilio limits messages that combine text and images to 5MB. If you try to send, say, an MMS message combining text and video, and the total size is greater than 5MB, Twilio will prevent the message from sending. Before sending out a large number of messages, it's a good idea to test your communications on various handsets using different file formats and sizes. See what works and what doesn't.
Twilio, Short Codes and MMS Messages
If you're using a Twilio short code, keep in mind that it doesn't automatically support MMS messages. You can add MMS capabilities for a one-time fee of $500. This is different than regular "long codes" (phone numbers) where MMS is usually automatically supported.
If you're not sure whether your account supports MMS messaging, check your Twilio Console. If you only see "Capabilities: SMS" and MMS is not listed, then it's likely you haven't purchased MMS for your short code.
See the setting up Twilio section for more information on configuring Twilio as your SMS provider.
Long Code Throttling
It's still a bit like the Wild West out there when it comes to SMS and MMS. Each carrier has its own rules and practices. For many carriers, sending or receiving too many messages too quickly will set off spam warnings, which results in messages either not being sent or not being received. This can be a real problem when you need to send information to a lot of people at once.
Fear not. We've got you covered. Out of the box, Rock comes configured with Long Code Throttling. This slows the delivery of non-short code numbers. By default, it is set to 500 milliseconds, or half of a second, which is the rate we've found works best for both speed and reliable delivery. You can modify the rate, though, by changing your Twilio transport settings (Admin Tools > Settings > Communication Transports). You can also disable Long Code Throttling altogether. Keep in mind, though, that this may result in your messages not being delivered.