Why it matters
Carrier spam filters can block messages before they reach contacts. Knowing the common causes and how to avoid them helps maintain strong deliverability, keep conversations flowing, and protect your sender reputation.
Key Concepts
Spam-flagged message: A message blocked by a carrier because its content or sending behavior matches patterns associated with spam.
Opt-out: When a contact blocks your number or stops receiving messages, intentionally or unintentionally.
S.H.A.F.T. rules: Carrier restrictions covering content related to Sex, Hate, Alcohol, Firearms, and Tobacco.
Step-by-Step: Understand Why a Message Was Flagged
Review whether the contact may have blocked your number without sending STOP.
Check recent message activity for high spam-report patterns.
Look for phone numbers included inside your message (other than your sending number).
Identify content that may match common spam patterns on carrier networks.
Consider whether the carrier may have incorrectly flagged the message.
Step-by-Step: Resolve a Spam-Flagged Message
Call the contact and ask them to text START back to your number.
Edit and resend the message without including additional phone numbers.
Adjust the message wording to remove high-risk or repetitive phrases.
Wait and try sending again later, or schedule it for a later time.
If the block persists, contact Whippy Support to request a carrier review.
Tips and Best Practices
Message only contacts who have clearly opted in.
Keep messages short and avoid multi-segment text blocks.
Avoid promotional or triggering language such as “URGENT”, “BUY NOW”, or excessive capitalization.
Do not include additional phone numbers unless required.
Monitor campaign performance for changes that may trigger carrier filters.
Understanding S.H.A.F.T. Rules
Carriers automatically block content referencing the following categories:
Sex: Avoid explicit or sexual content.
Hate: Never include discriminatory or hateful language.
Alcohol: Follow age-restricted guidelines; avoid promotional alcohol content.
Firearms: Do not promote or reference weapons or violence.
Tobacco: Avoid messaging that promotes tobacco products.
Complying with these rules helps ensure messages stay deliverable and aligned with carrier policies.
Troubleshooting
Issue | Possible Cause | Fix |
Message continues to be flagged | Content closely resembles other blocked messages | Rewrite wording and remove risky terms |
Contact not receiving messages | Contact has blocked your number | Ask them to send START |
Campaign delivery drops | High spam complaints or repetitive messaging pattern | Confirm opt-in, adjust message content |
Flagged without clear reason | Carrier filtering error | Retry later or request carrier review |