Rate Limited Emails - Resolve Throttling and Sending Limits

Modified on: Wed, 1 Jul, 2026 at 5:04 AM

EMAIL DELIVERABILITY

Rate Limited/Throttled Email Delivery: Complete Resolution Guide

Why recipient servers slow down your sending, and how batch sending gets you back to normal delivery.

What You'll Learn

Your emails are being temporarily delayed or rejected because recipient servers are limiting the rate at which they accept messages from your sending domain or IP address. This is a protective measure that email providers use to prevent spam and manage server load, but it can affect legitimate senders when volume spikes or reputation drops.

Table of Contents

What's Happening?

Quick Diagnosis: Identifying Rate Limiting Issues

Understanding Rate Limiting and Throttling

Step-by-Step Rate Limiting Resolution

Recovery Timeline and Expectations

Prevention Best Practices

Still Having Issues?

Frequently Asked Questions

What's Happening?

Quick Diagnosis: Identifying Rate Limiting Issues

Common Rate Limiting Bounce Messages

"The recipient's server is temporarily limiting or delaying incoming messages due to high volume or policy"
"The sending server is temporarily restricted due to high volume or low reputation"
"The recipient is receiving too many emails too quickly, so further messages are temporarily blocked"
"Yahoo is temporarily deferring messages due to high volume or user complaints"
"The recipient's mailbox has reached its hourly message receiving limit"
"The receiving server delayed or rejected the message due to too many delivery attempts"
"The recipient server is temporarily limiting or rejecting messages due to high sending volume"
"The sending server is temporarily deferring messages due to high volume or user complaints"

Understanding Rate Limiting and Throttling

Key Concepts

Rate Limiting Fundamentals

Temporary Protection: Rate limits are usually temporary restrictions, not permanent blocks.
Volume-Based: Triggered when you send too many emails too quickly to the same provider.
Reputation-Influenced: Lower sender reputation leads to stricter rate limits.
Provider-Specific: Each email provider (Gmail, Yahoo, Outlook) has different thresholds.
Recoverable: Most rate limiting resolves within hours to days with proper adjustments.
Auto-Handled Bounces: The platform automatically marks invalid addresses, helping maintain list quality.

Rate Limiting Categories

Volume-Based Throttling

Too many emails sent in a short time period
Exceeding hourly or daily sending limits
Sudden spikes in sending volume

Reputation-Based Restrictions

Low sender score triggering conservative limits
Recent complaint or bounce rate increases
New sending domain with limited history

Recipient-Level Limits

Individual mailbox receiving limits exceeded
Domain-wide incoming message restrictions

Step-by-Step Rate Limiting Resolution

Step 1

Implement a Batch Sending Strategy

Use the batch sending feature to control email volume:

Access Campaign Creation
- Go to Marketing → Campaigns → Create Campaign.
- Select Email Campaign type.
- Choose your email template and audience.
Configure Batch Sending
- In the campaign setup, look for Scheduling Options.
- Select Batch Sending or Schedule in Batches.
- Set conservative batch sizes: start with 50–100 emails per batch.
- Space batches 2–4 hours apart initially.
Pause Existing High-Volume Campaigns
- Navigate to active campaigns and pause any sending large volumes.
- Convert them to batch sending format.
- Prioritize essential communications only.

Batch Sending Success Indicators

Fewer bounce messages mentioning "high volume" or "too quickly."
Improved delivery rates within each batch.
Emails processing smoothly without immediate rejections.

Reference: Batch Email Guide

Step 2

Monitor External Reputation Metrics

Since the platform doesn't provide built-in reputation monitoring, use these external tools:

Check Sender Score
- Visit senderscore.org.
- Enter your sending domain or IP address.
- A score below 70 indicates reputation issues contributing to rate limiting.
Verify IP Reputation
- Use mxtoolbox.com/blacklists.aspx.
- Check if your sending IP appears on any blacklists.
- Monitor for "policy" or "reputation" related listings.
Provider-Specific Tools
- Gmail: Check Google Postmaster Tools for reputation data.
- Microsoft: Review Smart Network Data Services (SNDS).
- Yahoo: Monitor Yahoo Sender Hub feedback.

Step 3

Leverage Automatic Bounce Handling

The platform automatically manages bounced addresses to improve your sender reputation:

Review Bounce Reports
- Go to Marketing → Email → Reports.
- Check bounce rates and types in your recent campaigns.
- Note that hard bounces are automatically marked as invalid.
Verify Invalid Contact Management
- Navigate to Contacts → All Contacts.
- Filter by Invalid or Bounced status.
- Confirm these contacts are excluded from future campaigns.
Focus on Engaged Segments
- Go to Contacts → Smart Lists.
- Create segments based on recent email engagement.
- Prioritize batch sending to your most engaged contacts first.

Step 4

Verify Sending Domain Authentication

Ensure proper domain authentication to improve reputation:

Check Domain Settings
- Go to Settings → Email Services → Sending Domain.
- Confirm SPF, DKIM, and DMARC records show as verified.
- Look for green checkmarks or "Verified" status.
Update DNS Records if Needed
- Copy any unverified DNS records.
- Add them to your domain's DNS settings.
- Wait 24–48 hours for propagation and re-verification.

Recovery Timeline and Expectations

Phase	Action	Expected Outcome	Success Metric
Phase 1: Immediate Relief (2–6 hours)	Switch to batch sending with conservative volumes	Reduced bounce rates, fewer "too quickly" messages	50% reduction in rate limiting bounces
Phase 2: Short-Term Stabilization (1–3 days)	Gradually increase batch sizes with engaged contacts	Consistent delivery within each batch	80%+ delivery rate to high-engagement segments
Phase 3: Full Recovery (1–2 weeks)	Return to larger batch sizes with reputation monitoring	Normal delivery rates across all segments	Less than 2% rate limiting bounces

Prevention Best Practices

Smart Batch Management

Conservative Start: Begin with small batches (50–100 emails) and increase gradually.
Consistent Timing: Space batches evenly throughout business hours.
Provider Awareness: Consider smaller batches for strict providers like Yahoo.
Engagement Priority: Send to most engaged contacts first in each batch.

Ongoing Reputation Maintenance

Weekly Monitoring: Check sender score and blacklist status weekly.
Bounce Rate Tracking: Monitor bounce rates in campaign reports.
Trust the Platform: Let automatic bounce handling maintain list quality.
Content Quality: Avoid spam trigger words and maintain professional formatting.

Still Having Issues?

If you continue to experience rate limiting challenges after implementing batch sending:

Reduce Batch Sizes Further: Try 25–50 emails per batch with longer intervals.
Segment by Provider: Create separate batches for Gmail, Yahoo, and Outlook recipients.
Review Content: Analyze email content for elements that might trigger aggressive filtering.
Consider Timing: Avoid peak sending times when providers are most restrictive.

Frequently Asked Questions

Q: Does batch sending affect how long a campaign takes to complete?

Yes. Spreading a send into smaller batches with gaps between them naturally extends total completion time compared to sending everything at once, but that trade-off is what keeps recipient servers from throttling you.

Q: Can I mix batch sending with regular scheduled sends?

Yes, though during active rate limiting it's best to convert all high-volume campaigns to batch format temporarily. Once delivery stabilizes, you can return non-affected campaigns to normal scheduling.

Q: How do I know which provider is throttling me?

Check your bounce report for the specific bounce message text and recipient domain. Messages mentioning Yahoo, Gmail, or Outlook by name, or referencing that provider's typical deferral language, point to that provider specifically.

Q: Will batch sending permanently reduce my daily send capacity?

No. Batch sending is a temporary control measure. As your reputation stabilizes and rate limiting bounces drop, you can gradually increase batch sizes and frequency back toward your normal sending volume.

Q: Is rate limiting the same as being blacklisted?

No. Rate limiting is a temporary throttle based on volume or reputation at a single provider, while blacklisting is a more severe listing that can affect delivery across multiple providers. Rate limiting typically resolves in hours to days without any delisting process.

Q: How small should my batches be for stricter providers like Yahoo?

Start smaller than your general batch size — consider 25–50 emails per batch for Yahoo recipients specifically, with longer gaps between sends, and increase only as delivery to that provider stabilizes.