The average person spends up to six hours per day on their phone and checks it once every 10 to 12 minutes.

 

This provides an enormous opportunity for brands to engage customers anytime, anywhere.

 

With 98% open rates and click-through rates as high as 40%, SMS is a potent way to interact with consumers worldwide at scale. However, if they don’t receive your messages, all your hard work goes to waste.

 

Deliverability is a key element of a successful SMS marketing campaign. SMS deliverability refers to the number of texts that successfully reach the intended recipients. This shouldn’t be confused with throughput, which is how fast SMS messages reach receivers. 

 

Higher deliverability rates mean that your messages are being received and seen by your target audience, which is critical for effective outreach.

 

Unfortunately, dropped SMS messages can and do happen. Businesses must take proactive steps to boost SMS deliverability to ensure the success of their marketing and customer communications. 

5 Reasons SMS Messages Aren’t Delivered 

 

Several factors can contribute to SMS deliverability issues. Often, the main culprits behind undelivered messages are carriers, content, and dirty data. 

Carrier Filtering 

 

Network carriers are responsible for sending texts and reducing fraud, spam, and restricted content through stringent rules and regulations. Messages that contain excessive links or emojis, inconsistent capitalization or all-caps, and spam-triggering words, such as “free,” “cheap,” or “winner,” increase the risk of undeliverability and impact your sender reputation. 

Poor List Quality

 

When was the last time you scrubbed your SMS subscriber list of dirty data? Invalid numbers, like landlines or incorrectly formatted ones, cause undelivered texts, just like invalid email addresses cause bounced emails. 

Network Coverage and Technical Glitches 

 

Weak signals, low coverage, device issues, and other technical problems can prevent SMS delivery. Additionally, network outages can cause delayed or failed messages. 

Lack of Permission 

 

Businesses must obtain explicit consent from recipients before sending them SMS messages. Messages can be flagged as spam and filtered or blocked without this permission. 

Subpar SMS Provider 

 

Carriers don’t just assess sender reputation and SMS content. They also evaluate the reputation of the SMS provider you’re using. If your provider’s platform has a high volume of spam reports, you may experience a substantial decrease in deliverability. 

Signed, Sealed, and Delivered: Best Practices for SMS Deliverability Success 

 

Use these seven best practices to improve your deliverability and keep your campaigns firing on all cylinders.

Keep Messages Short and Sweet

 

Concise messages are more likely to pass carrier filters and are easier for users to digest. Aim for under 160 characters when possible. Avoid links that look suspicious or long strings of emojis and symbols.

Validate Numbers with Mitto’s Number Lookup

 

Before you hit send, use Mitto’s Number Lookup tool to validate your recipient list. This powerful tool checks whether a number is active and reachable, saving you money and improving your sender reputation.

 

Number Lookup also helps:

  • Detect landlines or VoIP numbers that can’t receive SMS
  • Avoid repeat sends to numbers that have been deactivated or reassigned
  • Identify the correct format for international numbers

Avoid Carrier Filtering

 

While carriers don’t always publish their filtering criteria, you can steer clear of common triggers by:

 

  • Avoiding all caps and excessive punctuation (!!!)
  • Not using shortened URLs that carriers may flag
  • Sending personalized, relevant content that users expect

 

Testing different message variants with A/B testing in Mitto’s Campaigns platform can help you find formats that consistently bypass filters.

Use a Provider with Secure, Direct Connections

 

Mitto’s global network of 800+ direct carrier connections ensures your messages travel the most reliable and secure paths. Unlike providers that rely on indirect or “grey” routes, Mitto offers:

 

  • Lower latency
  • Higher deliverability rates
  • Enhanced security and compliance

Steer Clear of Grey Routes

 

Grey routes may seem like a cheap shortcut, but they’re unreliable and often lead to message blocking or delays. They also put your brand at risk of compliance violations.

 

You protect your messages and sender reputation by partnering with a CPaaS provider like Mitto, which uses legitimate, high-quality routes.

Get the Timing Right

 

Even the most deliverable message can miss its mark if it arrives at the wrong time. You can also risk noncompliance if you send texts before 8 a.m. or after 8 p.m. local time.

 

Use data to determine when your audience is most responsive. With Mitto’s Campaigns, you can schedule sends for optimal engagement across time zones and countries.

Ensure Relevance and Consent

 

Only send messages to users who have opted in to receive them. Relevance drives engagement, and engagement drives deliverability. Deliver timely, useful, and expected content to avoid high opt-out rates and spam reports.

Optimize SMS Deliverability with Mitto

 

Improving SMS deliverability isn’t a one-time fix. It’s an ongoing monitoring, learning, and optimizing process. The good news? With the right tools, strategies, and a trusted CPaaS partner like Mitto, you can ensure your messages reach their full potential (and their recipients).

 

Snag our comprehensive guide, Best Practices: A2P SMS Deliverability, for more expert guidance on boosting SMS deliverability rates.