Why don’t my contacts receive the SMS I sent

If you notice that your SMS shows Delivered, but your recipients never received them, it is possible that the delivery providers have restricted your content.

If this is your case, we will help you understand why it happens and how to solve it 🙂


What are shipping providers

At Doppler we use different telecommunications operating companies in each country, as service providers for sending SMS to your contacts.

What should you take into account? Each country has its own restriction on the type of content that messages sent contain. If that content does not meet certain established standards, your messages could be restricted.

Another point to highlight is that the telecommunications operating companies validate the content of the SMS links through a process that can take between 24 and 48 hours, before effective delivery.

Next, we explain what you must take into account so that your campaigns are successful.

Tips and restrictions

There are some points that you must take into account depending on the country of the recipient of your message and some general good practices that will help you maximize the effectiveness of your shipments.


Always ask permission

Never send an SMS to a client who has expressly not agreed to receive your messages. To accomplish this, make sure all of your contacts have opted-in to your contact list.

What is opt-in? We call this the process by which a user explicitly gives us permission to send him messages. If you want to learn more about what opt-in is and how to configure it, you can visit our article “Single and Double Opt-in Forms: What are they and how can i set them up

This guarantees your consent and prevents us from becoming spammers. Also, make sure you don’t put up unnecessary obstacles if your contacts want to opt out, that is, unsubscribe from your list.


Ensure the deliverability of your messages

We recommend that when creating the content of your SMS, you use customizable shorteners that allow you to add your own verified domain, which leads to the correct and reliable website. Why do we advise this? Because those messages that are sent with shortened links of the bit.ly type will not be delivered correctly for security and phishing reasons.

In this instance, security experts and the corresponding telephone companies will review the contents of the SMS to detect and avoid malicious links or inappropriate content for users.

Check the schedule

Some countries may restrict your message depending on the time you send it.

Be sure to send your SMS during the day and avoid night hours. Besides, beyond the restrictions of each country, your contacts will thank you for not waking them up in the early morning 😉


Keep the rules in mind

Some regions have specific requirements for SMS campaigns. If you violate the regulations of the places where your customers reside, it is very likely that your contacts will not receive your messages.

Therefore, we have detailed some important points for you to keep in mind when sending text messages to the following countries:


❌​ Political content is restricted



✔️ Requires opt-in to receive marketing content or promotions

✔️ URLs have to be approved by the sending provider

✔️ The option to unsubscribe from SMS must be provided

❌ Content about religion, politics, abortion, or that infringes on third party intellectual property is restricted


❌​ Content about alcohol, drugs, or politics is restricted


✔️​ Requires opt-in to receive political content. In addition, you must specify that the message is “Paid political content”
✔️ The time allowed to send promotional content is from 8:00 a.m. to 9:00 p.m. (Colombia Time). Messages sent outside these hours will be delivered at 8:00 a.m. the next day
✔️ Requires mentioning the used shipping tool. From Doppler, we will add the text “Via Doppler” at the end of each message
✔️ URLs have to be approved by the shipping provider


✔️​ Requires opt-in. The user’s consent must be explicit and very specific
That is to say that, for example, it cannot be included in an instance where he/she must accept a large number of Terms and Conditions. The person must be fully aware of what he/she is accepting
✔️ Right to request opt-out


✔️​ Requires opt-in
✔️ The time allowed to send promotional content is from 7:00 a.m. to 9:00 p.m. (Central Time)
❌​ Religious, political, or sexual content is restricted


✔️​ Opt-in required to receive marketing content or promotions
✔️ The time allowed to send promotional content is from
-Monday to Friday from 8:00 a.m. to 8:00 p.m. (Peru Time)
-Saturdays from 9:00 a.m. to 1:00 p.m. (Peru Time)
Transactional SMS have no time restriction
❌​ Political content is restricted


You already know everything important to start sending successful SMS 🙂

And remember that if you have more questions, you can contact our Customer Service team via WhatsApp. We will be happy to help you with whatever you need.



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