SMS Best Practices to Avoid Being Blocked

Jasper Jasper

While Kixie will always send your SMS messages to their destination, it's possible that the recipient's mobile phone carrier i.e. AT&T/Verizon may block delivery of the SMS message due to a number of factors related to the SMS message itself, which of course is completely beyond Kixie's control. 

Best Practices to Avoid SMS Messages Being Blocked by Receiving Carriers

  • Keep your messages short and conversational, and avoid lengthy/marketing-heavy messages. This especially applies to your first-ever SMS message to someone.
  • The first-ever message to the prospect's number ideally should be a conversational introduction like "Hi (first name)". Then, delay for at least a few seconds, and send the remainder of your text, and then send whatever un-shortened link you want to send (so 3 total messages). This is easiest to accomplish with auto-SMS via Zapier or directly from a HubSpot workflow, which of course also has the benefit of standardization and automation, so you don't have to trust your reps to remember to send the text the right way.
    • The initial "Hi (first name)" text increases the chances of subsequent messages being allowed through by the mobile carrier, especially if you plan on sending a link afterwards. And again - never use shortened links like or tinyurl.

Reasons an SMS Message Would be Blocked by a Recipient's Mobile Phone/Carrier

  • The message contains a URL (especially a shortened link such as or tinyurl)
    • If you're going to use a URL, it is worse if it is a repetitive URL(s), and worse still if it is a shortened link (such as
      • repetitive url example:
  • The same message has been sent repeatedly - without variation or personalization 
    • workaround - use [fname] in your SMS template to personalize it automatically, or use the rep's first name in your auto-sms via Zapier.
  • More than 200 SMS/day are sent per SMS number
    • workaround - call more, text less!
  • Long texts
  • The receiving mobile device blocks unknown SMS numbers as a rule
    • perhaps the user downloaded an anti-spam app
      • perhaps the mobile device may also send SMS messages from numbers for which there has never been a phone call in the past, right to spam
        • workaround - call your prospect's number before texting them
  • Your number was manually reported as spam to a carrier(s).
    • workaround - you can easily replace any agent's DID/SMS DID with a new one anytime which will fix this issue.
  • The ratio of incoming to outgoing SMS on an SMS Number is more than 1:3
  • The same message is sent from the same number within 5-10 seconds of the first message

Please email or reach out to your Account Manager with any questions about auto-SMS and/or SMS templates.