SMS Marketing Best Practices

SMS Messaging – SMTP vs SMPP

Did you know that not all text messages are created equal? In fact, there is such a disparity between the two types of text messaging available to groups and organizations, that we thought it best to write an entire post about the differences. Hopefully, this will help to not only educate our current users but also our future users that are doing their research into the different group text messaging websites currently available.

The first thing to do is to clarify and define the two different types of text messaging. These differences are very clear and stem from the method these messages are sent from the website to the cell phone provider (AT&T, Verizon, etc.)

The first method which is commonly referred to as “Email To SMS” or “Standard Delivery” text messaging is technically called “Simple Mail Transfer Protocol” or SMTP. To send a text message via the SMTP method, all one must do is attach their phone number to the beginning of the carrier’s SMTP email address and send it just like any other email. To give you an example, I have a Verizon phone and their SMTP email address is “”. To send myself a text message, all I have to do is send an email with my mobile number attached to the front of that address (i.e. and whatever I put in the body of that email will appear on my phone.

The second method which is commonly referred to as “Short Code” or “Express” text messaging is technically called “Short Message Peer-to-Peer Protocol” or SMPP. This is the preferred method as it is used when you are sending text messages back and forth between a friend on your own mobile phone. These messages go through the carrier’s cell network as compared to the carrier’s email network with SMTP.

1. Cost of Sending: The cost to set up an SMTP website is very small, being that all you need is an email server and some bandwidth and you are up and running. This makes SMTP websites a dime a dozen and notorious for being used to generate text message SPAM. On the other hand, the costs to set up an SMPP website are much greater in terms of both invested time and capital. To start the process of being approved for SMPP messaging a company must go through a 6-8 week approval process, in which carriers rigorously test the product to make sure it meets all the required standards. In addition to this, the company must also partnership with an aggregator who will charge them connection, setup, and most importantly, a per-message fee to send each text message.

2. Message Speed: SMTP is not a direct connection to carriers and as a result, messages are extremely slow and are in no way guaranteed to end up at the destination. We have seen messages sent through the SMTP gateway take 24-48 hours to reach their destination. On the other hand, SMPP has priority routing and is guaranteed to be a much faster rate with a 99% success rate. From our experience, it’s very rare to not see SMPP messages received within a few seconds of sending them.

3. Legal issues: The SMTP gateway was only built for personal use, and carriers have made it very clear that any use of this gateway for commercial purposes is in direct violation of their terms of service. In addition to the carriers not allowing commercial messaging through their SMTP gateway, the Federal Communications Commission (FCC) adopted rules that prohibit sending unwanted commercial SMTP messages to wireless devices. With the FCC governing these messages, any violations would be considered a federal offense and punishable by the full extent of the law.

4. Reliability: What happens when a carrier changes their email domain that you send SMTP messages to? One sure thing is that they won’t tell you about these changes and all of a sudden your messages won’t be reaching their intended recipients. When you send messages via SMPP, your connection will always be the same because websites utilizing SMPP have a direct connection to the carriers which doesn’t require us to know an email address.

5. Look & feel of messages: Plain and simple, SMTP messages look cluttered and extremely unprofessional. To illustrate this point, check out the image below that puts both SMPP and SMTP messages side by side for you to compare with your own eyes.

6. No easy way to subscribe: This is the coolest part of using SMPP messaging, people can join a group directly from their own mobile phone by texting a keyword (ie – VIP, DELTAU, BBALL) to our short code number 68398. You will not find that with SMTP messaging.

Well, hopefully, you have learned that not all text messages are the same and when looking for a website that offers the ability to send out mass text messages, make sure you are choosing SMPP.


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