Decoding Deliverability: Why Your Political Text Messages Are Ending Up in Spam (and How to Fix It)

You've crafted the perfect message. Your volunteers are ready. You hit send on 50,000 texts. But only 38,000 actually reach voters. The other 12,000? Filtered, blocked, or lost somewhere in the carrier networks.

That's 24% of your voter universe - and potentially the margin of victory - disappearing into the void.

Message deliverability is the single most important technical factor in P2P texting success. A platform with 85% delivery versus 97% delivery means 12,000 fewer voters reached per 100,000 messages. In close races, that's catastrophic.

This guide decodes why messages get filtered, how carrier spam detection works, what hurts your sender reputation, and - most importantly - exactly what you can do to maximize deliverability.

Understanding SMS Deliverability

The Message Journey

What happens when you send a text:

1. Your platform → Sends message to SMS aggregator
2. Aggregator → Routes to appropriate carrier network
3. Carrier network (AT&T, Verizon, T-Mobile) → Applies spam filters
4. Recipient device → Delivers (or doesn't)

Failure can happen at any stage.

Delivery Rate Benchmarks

Political Comms average: 97.8% delivery

Why Low Delivery Rates Matter

In a 100,000 message GOTV campaign:

Platform with 97% delivery:

• 97,000 voters reached
• Estimated 2,910 additional votes (3% turnout lift)

Platform with 85% delivery:

• 85,000 voters reached
• Estimated 2,550 additional votes (3% turnout lift)

Difference: 360 fewer votes (12% reduction in impact)

In a race decided by 500 votes, deliverability determines the outcome.

The Three Carrier Giants and How They Filter

AT&T, Verizon, and T-Mobile

These three carriers control 98%+ of the U.S. mobile market. Each applies spam filtering differently.

How Carrier Filtering Works

Carriers use algorithms to detect spam based on:

1. Sending patterns:

• Volume per phone number
• Sending speed
• Time of day
• Consistency

2. Content analysis:

• Spam trigger words
• Link reputation
• Message structure
• ALL CAPS usage

3. Engagement signals:

• Reply rates
• Opt-out rates
• Block rates
• Complaint rates

4. Sender reputation:

• Historical performance
• 10DLC registration status
• Campaign Registry trust score
• Platform reputation

Carrier-Specific Behaviors

AT&T:

• Strictest filtering
• Heavily weights sender reputation
• Fast to block problematic senders
• Requires strong 10DLC registration

Verizon:

• Moderate filtering
• Balanced approach
• Focuses on engagement metrics
• Generally reliable delivery

T-Mobile:

• Lightest filtering (but improving)
• More permissive historically
• Increasing spam detection sophistication
• Good for political messages

Why carrier-specific reporting matters: If AT&T blocks your messages but Verizon delivers fine, you need to know to fix AT&T specifically.

Top 10 Reasons Your Messages Get Filtered

1. Poor or Missing 10DLC Registration

The problem: Messages from unregistered senders get filtered aggressively.

How it happens:

• Skipped 10DLC registration
• Incomplete registration
• Generic "business" registration (not political-specific)
• Expired or rejected registration

The fix:

• Complete proper political campaign 10DLC registration
• Use political-specific campaign use cases
• Maintain good standing with The Campaign Registry
• Re-register if registration expires

Political Comms solution: We handle 10DLC registration in 24-48 hours with political-specific workflows.

2. High-Volume Sending from Single Numbers

The problem: Sending thousands of messages from one phone number looks like spam.

How it happens:

• Insufficient phone number pool
• Poor number rotation
• All messages funneled through few numbers

Volume limits that trigger filters:

• More than 200-300 messages per number per day

The fix:

• Use multiple phone numbers
• Rotate sending across numbers
• Match numbers to local area codes where possible
• Never exceed ~250 messages per number per day

3. Low or Zero Reply Rates

The problem: If nobody replies to your messages, carriers assume recipients don't want them (spam indicator).

How it happens:

• One-way broadcast messages
• No questions or engagement prompts
• Messages that don't invite replies

Healthy reply rate: 10-25% Red flag reply rate: Under 5%

The fix:

• Ask questions: "Can we count on your vote?"
• Invite replies: "Reply YES if you can help!"
• Use P2P (human conversations) vs. A2P (broadcast)
• Train volunteers to engage in real conversations

4. High Opt-Out Rates

The problem: If many people opt out (text STOP), carriers flag your sender as spam.

How it happens:

• Texting without consent
• Poor targeting (wrong audience)
• Too-frequent messaging
• Annoying or irrelevant content

Healthy opt-out rate: Under 0.5% Warning rate: 0.5-1% Critical rate: Over 1%

The fix:

• Only text people who opted in or have existing relationship
• Limit message frequency (don't spam)
• Send relevant, valuable messages
• Honor opt-outs immediately

5. Spam Trigger Words and Phrases

The problem: Certain words and phrases trigger spam filters.

Common spam triggers:

• "FREE" (especially all caps)
• "Click here NOW"
• "Congratulations, you won"
• "Act now" / "Limited time"
• Excessive exclamation points!!!
• ALL CAPS MESSAGES

The fix:

• Avoid spam trigger words
• Use conversational, natural language
• Don't use ALL CAPS
• Limit exclamation points (1 per message max)
• Write like a human, not a marketer

Good message:

Hi Sarah! This is Alex with Johnson for Congress. Can we count on your vote on November 5?

Spam-triggering message:

URGENT!!! CLICK NOW for a FREE chance to WIN!!! Limited time!!!

6. Suspicious or Unbranded Links

The problem: Generic URL shorteners (bit.ly, tinyurl) are heavily filtered because spammers use them.

How it happens:

• Using generic link shorteners
• Unrecognizable domains
• Links to suspicious-looking sites
• Too many links in one message

The fix:

• Use branded link shorteners (e.g., johnsonforCongress.com/vote)
• Keep links recognizable and trustworthy
• Limit to 1 link per message
• Ensure link destinations are secure (HTTPS)

7. Poor Message Formatting

The problem: Messages that look like spam get treated like spam.

What triggers filters:

• Multiple messages in rapid succession (looks automated)
• Identical messages sent to many recipients simultaneously
• Weird characters or encoding issues
• Excessively long messages

The fix:

• Vary message timing slightly (P2P helps with this)
• Personalize messages (different for each recipient)
• Keep messages under 300 characters (or split intelligently)
• Test messages before large sends

8. Weak Sender Reputation

The problem: Carriers track sender reputation over time. Bad history = more filtering.

What hurts reputation:

• High historical opt-out rates
• Past spam complaints
• Low engagement
• Violations or blocks

What builds reputation:

• Consistent delivery of wanted messages
• High reply rates
• Low opt-out rates
• Proper 10DLC registration
• Clean sending patterns

The fix:

• Build reputation over time (don't launch with huge volume)
• Start small, scale gradually
• Maintain high engagement
• Never text without consent

9. Timing and Sending Patterns

The problem: Unnatural sending patterns trigger spam detection.

What looks suspicious:

• Sending at 2 AM
• Sending identical messages to thousands simultaneously
• Sudden volume spikes (0 to 50,000 in one day)
• Perfectly robotic timing

The fix:

• Send during reasonable hours (9 AM - 9 PM)
• Ramp volume gradually (start smaller, scale up)
• Use P2P (natural human sending patterns)
• Respect time zones

10. Platform and Aggregator Reputation

The problem: Your deliverability depends partly on your platform's overall reputation.

How it happens:

• Platform with bad actors (spammers) affects all users
• Shared infrastructure means shared reputation
• Poor platform carrier relationships

The fix:

• Choose platforms with:
  • Direct carrier relationships
  • Strong reputation
  • Political campaign specialization
  • 95%+ average delivery rates

Political Comms advantage: Direct carrier relationships and 97.8% delivery rates.

How to Monitor Your Deliverability

Key Metrics to Track

1. Overall delivery rate: Messages delivered ÷ Messages sent

Target: 95%+

2. Carrier-specific delivery: Break down by AT&T, Verizon, T-Mobile

Why: Identifies carrier-specific issues

3. Delivery speed: How long until messages are delivered?

Target: 90%+ delivered within 5 minutes

4. Failure reasons: Why did messages fail?

• Invalid number
• Carrier block
• Network error
• Spam filter

5. Reply rate: Replies ÷ Messages delivered

Target: 15-25% for GOTV, 10-20% for fundraising

6. Opt-out rate: Opt-outs ÷ Messages delivered

Target: Under 0.5%

Warning Signs

🚨 Delivery rate drops below 90% 🚨 Carrier-specific delivery varies widely (AT&T 70%, Verizon 95%) 🚨 Reply rate under 5% 🚨 Opt-out rate over 1% 🚨 Delivery speed slow (hours, not minutes)

Proactive Steps to Maximize Deliverability

Before You Send

• Complete 10DLC registration properly
• Build sender reputation gradually (start small)
• Verify contact list quality (remove landlines, invalid numbers)
• Craft engaging, conversational messages
• Avoid spam trigger words
• Use branded, trustworthy links
• Set up multiple phone numbers
• Test messages to yourself first

During Campaign

• Monitor delivery rates in real-time
• Track carrier-specific performance
• Watch reply and opt-out rates
• Adjust if delivery drops
• Respond to replies quickly (boosts engagement)
• Vary sending times and patterns
• Scale volume gradually

After Campaign

• Analyze delivery data
• Identify what worked/didn't
• Document lessons learned
• Share insights with team

Fixing Common Deliverability Problems

Problem: Low AT&T Delivery

Symptoms: AT&T 75%, Verizon 97%, T-Mobile 96%

Likely causes:

• Weak 10DLC registration
• Poor sender reputation
• High volume from single numbers

Fixes:

1. Review 10DLC registration (ensure political-specific)
2. Reduce volume per number (use more numbers)
3. Improve engagement (ask questions, invite replies)
4. Contact platform support for carrier relationship help

Problem: Sudden Delivery Drop

Symptoms: Delivery was 95%, now 80%

Likely causes:

• Recent opt-out spike
• Spam complaints
• Content change triggered filters
• Volume spike

Fixes:

1. Check opt-out rate (>1% is problem)
2. Review message content for spam triggers
3. Reduce sending volume temporarily
4. Test with small batch before resuming

Problem: Slow Delivery

Symptoms: Messages take hours to deliver

Likely causes:

• Network congestion
• Low priority routing (poor sender reputation)
• Platform issues

Fixes:

1. Check platform status
2. Send during off-peak hours
3. Improve sender reputation over time
4. Consider switching platforms if persistent

Problem: High Opt-Out Rate

Symptoms: Opt-outs over 1%

Likely causes:

• Texting without consent
• Too-frequent messaging
• Irrelevant content
• Wrong audience

Fixes:

1. Verify consent for all contacts
2. Reduce message frequency
3. Improve targeting and segmentation
4. Make messages more relevant and valuable

Platform Features That Improve Deliverability

What to Look For

1. Carrier-specific reporting: See delivery rates by AT&T, Verizon, T-Mobile separately

2. Direct carrier relationships: One hop to carriers (not through multiple aggregators)

3. Automatic number rotation: Distributes volume across phone numbers

4. Fast 10DLC registration: Political-specific workflows, 24-48 hour turnaround

5. Proactive monitoring: Alerts when delivery rates drop

6. Spam filter guidance: Warns about spam trigger words before sending

7. Real-time analytics: Monitor delivery rates during campaign

Political Comms features: ✅ Full carrier-specific reporting ✅ Direct carrier relationships ✅ Automatic number management ✅ 24-48 hour 10DLC registration ✅ Real-time delivery monitoring ✅ Content guidance

The Bottom Line

High deliverability requires:

• ✅ Proper 10DLC registration (political-specific, complete)
• ✅ Strong sender reputation (built over time)
• ✅ High engagement (15-25% reply rates)
• ✅ Low opt-outs (under 0.5%)
• ✅ Clean content (no spam triggers)
• ✅ Branded links (no generic shorteners)
• ✅ Smart volume management (multiple numbers, gradual scaling)
• ✅ Natural sending patterns (P2P, reasonable hours)
• ✅ Quality platform (direct carrier relationships)

Why it matters: 12,000 undelivered messages per 100,000 sent = 360 fewer votes in a GOTV program with 3% lift. In close races, deliverability determines outcomes.

What to avoid: ❌ Skipping 10DLC registration ❌ One-way broadcast messages ❌ Spam trigger words ❌ Generic link shorteners ❌ Texting without consent ❌ High-volume spikes ❌ Platforms with poor carrier relationships

Benchmark to hit: 95%+ delivery rate overall, consistent across all carriers

Over 2,000 campaigns trust Political Comms for 97.8% delivery rates, direct carrier relationships, and proactive deliverability monitoring.

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Ready to maximize your delivery rates? Get started with Political Comms today.

Experiencing deliverability issues? Contact our team - we'll diagnose and fix them.