Message Delivery

Sonar Message Delivery

With Sonar, campaigns and messages are intentionally sent out over a period of time to reduce the likelihood of carriers blocking due to spam. Sonar utilizes A2P (application to person) protocol for sending messages to improve deliverability rates. We offer toll-free, short code, and local numbers which helps increase deliverability. You will also be notified if your message made it to the customer’s device with full visibility on the status of your message to see if it’s in queue, sent, delivered, or possibly experienced an error.


What is Deliverability Rate?

SMS deliverability is a measure of the percentage of outgoing text messages which are received at their intended destination. There are a lot of criteria that determines whether or not your message will be delivered. Different carriers evaluate messages at their discretion, and the rules they use can change at any time. But, in general, they look at a common set of criteria when deciding whether or not to allow your messages on their network.

Message Deliverability Notifications

To help make sure none of your messages slip through the cracks, Sonar provides notifications on whether they made it to the customer’s device. This includes full visibility on the status of your message to see if it’s in queue, sent, delivered, or possibly experienced an error.

Message Status Terms Defined:

  • Queued - Sent to carriers for delivery
  • Sent - Received by carriers for delivery
  • Delivered - Received by end-user handset (phone)
  • Failed - Message could not be sent for a given reason

General Criteria Checklist

The Sender

  • Who is the sender?
  • What number are they using?
  • Have either been flagged for SPAM in the past?

How They Are Sending

  • What type of number are they sending from?
  • Is it a short code, toll-free, or a local number?
  • Are they sending person-to-person or high-volume, application-to-person (A2P) messages?

The Volume of Messages Being Sent

  • How many total messages are being sent?
  • How many messages are being sent per second?

Message Content

  • Does the message include links?
  • Are known link shortening services, like, used?
  • Does it contain suspicious phrases or illicit content?

Tips on How to Increase Message Deliverability

  • Make sure your two variants are sufficiently different from each other.
  • Try to personalize messages to the customer. Include properties like the customer’s first name by including: {{first_name}}
  • Be as colloquial as possible. The more machine-like you sound, the lower the response rates.
  • Try to mass message customers only after they’ve messaged you indicating they like text as a channel.
  • When you have to reach out first, introduce yourself as a person (“Hey, this is Andrew from Sonar” vs “Hey this is Sonar”)



Sonar still charges for messages that were blocked or unable to be delivered.