10-15%
Messages filtered as spam without proper setup
99%
Delivery rate with best practices
$0.01
Cost of a blocked message (wasted spend)
Why Messages Get Filtered
Mobile carriers (Verizon, AT&T, T-Mobile) actively filter SMS messages to protect consumers from spam. Understanding what triggers these filters is essential for maintaining high deliverability rates and ensuring your legitimate marketing messages reach their intended recipients.
Common Spam Filter Triggers
Suspicious Links
Shortened URLs (bit.ly, tinyurl), free link shorteners, and links to unknown domains trigger spam filters. Use branded short links or your own domain.
Spammy Keywords
Words like "FREE!!", "WINNER", "ACT NOW", "URGENT", and excessive use of caps or exclamation marks signal spam. Write naturally and avoid hype.
High Volume from New Numbers
Sending thousands of messages immediately from a new number looks suspicious. Warm up new numbers gradually over 2-4 weeks.
Identical Messages
Sending the exact same message to thousands of recipients signals mass spam. Use personalization and message variations.
Missing Opt-Out
Messages without opt-out instructions (STOP to unsubscribe) are more likely to be filtered. Always include opt-out options.
Best Practices for Deliverability
Use a verified toll-free number
Toll-free numbers with proper verification have the highest deliverability rates. Complete carrier registration before sending.
Warm up your sending number
Start with low volumes (50-100/day) and gradually increase over 2-4 weeks. This builds trust with carriers.
Use your own branded short links
Instead of bit.ly, use branded links like yourbrand.link/promo. This builds trust and avoids spam triggers.
Personalize every message
Include the recipient's name or unique details. Personalized messages are less likely to be flagged as mass spam.
Clean your contact list regularly
Remove invalid numbers and unengaged subscribers. High bounce rates hurt your sender reputation.
Only message opted-in contacts
Never buy lists or message people who haven't explicitly consented. This is the #1 cause of filtering.
Message Content Guidelines
Do This
- Write conversationally and naturally
- Use proper capitalization
- Include your business name
- Add clear opt-out instructions
- Use branded short links
- Personalize with first names
- Keep messages concise
Avoid This
- ALL CAPS MESSAGES!!!
- Excessive punctuation!!!!!
- Words like FREE, WINNER, URGENT
- Public URL shorteners (bit.ly)
- Dollar signs in amounts ($$$)
- Misleading sender info
- Messages without opt-out
Sample Messages: Before & After
❌ Likely to be filtered:
"FREE OFFER!!! You've WON a $500 GIFT CARD! Click NOW: bit.ly/abc123 HURRY expires TODAY!!!"
✓ Optimized for delivery:
"Hi Sarah! Your loyalty reward is ready - enjoy 20% off your next order at Acme Store. Use code THANKS20 by Friday: acme.co/shop - Reply STOP to opt out"
Monitor Your Deliverability
Key Metrics to Watch
Delivery Rate
Should be 97%+ for a healthy list
Bounce Rate
Keep under 3% by cleaning your list
Opt-Out Rate
Under 2% indicates healthy content
Carrier Errors
Track which carriers are blocking
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