When sending a large email deployment on shared IPs, should I send in batches?

Summary

When sending large email deployments on shared IPs, sending in batches is generally recommended for improved deliverability and sender reputation management. While some experts suggest that large deployments might be acceptable with established providers, consulting with your ESP is crucial to confirm their capabilities and specific recommendations. A gradual ramp-up, throttling sending volume, and monitoring deliverability metrics are essential practices. This approach helps avoid triggering spam filters and SMTP rate limits, maintain a good IP reputation, adhere to sending limits, and allows for adjustments during the deployment process. Segmenting email lists and sending targeted content in batches can also improve engagement.

Key findings

  • ESP Consultation: Checking with your ESP is vital to ensure they can handle the volume and advise on the best sending practices.
  • Gradual Ramp-Up: A gradual increase in sending volume, especially with new or shared IPs, is essential for maintaining a good sender reputation.
  • Throttling Volume: Throttling sending volume helps prevent being flagged as spam and maintains a consistent sending pattern.
  • Monitoring Metrics: Closely monitoring deliverability metrics like bounce rates, open rates, and click rates allows for timely adjustments.
  • Rate Limiting: Sending in batches helps avoid triggering SMTP rate limits imposed by email servers.
  • Segmentation Benefits: Segmenting email lists and sending targeted content improves engagement and deliverability.

Key considerations

  • IP Warm-up Status: Consider the warm-up status of the shared IPs before sending a large volume, as new IPs require a more gradual ramp-up.
  • SMTP Compliance: Comply with SMTP server requirements and best practices to avoid rate limiting issues and maintain deliverability.
  • Load Balancing: Ensure your ESP can handle the load and effectively balance traffic to avoid deliverability issues.
  • Reputation Monitoring: Regularly monitor your IP reputation using tools like Google Postmaster Tools and adjust sending practices accordingly.
  • Adherence to Limits: Adhere to sending limits imposed by email providers like Microsoft to prevent blocking or throttling.
  • Consistent Sending Patterns: Establish and maintain consistent sending patterns to build and preserve IP reputation, as email providers look for this consistency.

What email marketers say
8Marketer opinions

When sending a large email deployment on shared IPs, it's generally recommended to send in batches. This approach allows for better control over sender reputation, avoids triggering spam filters, and enables monitoring of deliverability metrics. Gradual ramp-up and throttling are essential for maintaining a positive sending reputation.

Key opinions

  • Sender Reputation: Throttling and gradual ramp-up are vital to maintain a good sender reputation on shared IPs.
  • Warming Up IPs: Gradually increasing sending volume is key when warming up shared IPs, and monitoring metrics will help.
  • Segmentation: Segmenting lists and sending targeted content in batches improves engagement and deliverability.
  • Monitoring Metrics: Closely monitoring bounce rates and other metrics during batch sending allows for adjustments to improve deliverability.

Key considerations

  • ESP Confirmation: Consult with your Email Service Provider (ESP) to confirm their specific recommendations for large deployments.
  • IP Warm-up Status: Assess how warmed up the shared IPs are before sending a large volume.
  • Traffic Volume: Consider the volume of traffic going to your website as a result of the email deployment.
  • Adherence to Limits: Sending in batches can help adhere to sending limits.
Marketer view

Email marketer from Mailchimp shares that segmenting large email lists and sending in batches can improve engagement and deliverability. By sending targeted content to smaller groups, you can monitor performance and adjust your strategy accordingly when sending a large deployment.

June 2023 - Mailchimp
Marketer view

Email marketer from Reddit shares that when sending large volumes on shared IPs, they always throttle the email volume and monitor the bounce rate very closely.

September 2023 - Reddit
Marketer view

Email marketer from Email Geeks recommends asking your ESP for confirmation, as it depends on how warmed up the shared IPs are. Sending might require batches depending on the circumstances.

August 2021 - Email Geeks
Marketer view

Email marketer from SendGrid explains that warming up shared IPs involves gradually increasing sending volume. Start with small batches and monitor deliverability metrics to ensure a positive sending reputation when doing large deployments.

July 2021 - SendGrid
Marketer view

Email marketer from Email Marketing Forum states that batch sending gives more control for monitoring open and click rates, so adjustments can be made during deployment.

November 2021 - Email Marketing Forum
Marketer view

Email marketer from Quora suggests that gradual send outs and monitoring deliverability helps avoid deliverability problems when using shared IPs for high-volume sends.

February 2023 - Quora
Marketer view

Email marketer from StackExchange discusses that breaking the email lists into smaller sets can prevent you exceeding email limits and allow you to build a better sending reputation.

November 2023 - StackExchange
Marketer view

Email marketer from Mailjet explains that throttling email sends on shared IPs is essential to maintain a good sender reputation. If sending a large volume, gradually increase the sending rate to avoid being flagged as spam.

December 2023 - Mailjet

What the experts say
4Expert opinions

The advice around sending large email deployments on shared IPs is somewhat varied. Some experts suggest large deployments are acceptable, particularly with established providers, but recommend checking with the ESP to confirm. Others emphasize the importance of a gradual ramp-up and consistent sending patterns to maintain a good IP reputation and avoid deliverability issues when using shared IPs.

Key opinions

  • Provider Capacity: Established email providers can often handle large email deployments.
  • Ramp-Up Importance: Gradual ramp-up is crucial, especially with new or shared IPs.
  • Volume Impact: Email volume significantly affects IP reputation, necessitating consistent sending patterns.

Key considerations

  • ESP Consultation: Always check with your ESP regarding their capacity and recommendations for large deployments on shared IPs.
  • Load Balancing: Ensure your ESP can handle the load and balance traffic effectively.
  • Monitoring Results: Closely monitor results and adjust your strategy accordingly when increasing email volume.
  • Sending Patterns: Establish and maintain consistent sending patterns to build and preserve IP reputation.
Expert view

Expert from Email Geeks shares that sending 6 million emails on shared IPs should be fine but recommends checking with the provider to be sure.

January 2024 - Email Geeks
Expert view

Expert from Word to the Wise answers questions about volume and IP reputation. She suggests that volume is a key factor when using shared IPs because email providers are looking for consistent sending patterns to ensure a good reputation. Sending in batches is important to maintain this consistency.

April 2022 - Word to the Wise
Expert view

Expert from Word to the Wise explains that when using new or shared IPs, a gradual ramp-up is essential, increasing volume slowly and monitoring results to avoid deliverability issues. She highlights a real world experience where smaller batches sent initially helped avoid issues.

April 2021 - Word to the Wise
Expert view

Expert from Email Geeks suggests talking to the ESP so they can load balance but suggests it is probably fine.

January 2023 - Email Geeks

What the documentation says
3Technical articles

Sending large email deployments in batches on shared IPs is recommended by documentation from RFC, Google Postmaster Tools, and Microsoft. This practice helps avoid triggering SMTP rate limits designed to prevent abuse, maintain a good IP reputation by enabling monitoring and adjustments, and adhere to email sending limits to prevent blocking or throttling.

Key findings

  • Rate Limiting: SMTP servers use rate limiting to prevent abuse, and batch sending can help avoid these limits.
  • IP Reputation: Maintaining a good IP reputation is crucial, and batch sending allows for monitoring and adjustments to minimize spam flags.
  • Sending Limits: Batch sending helps adhere to email sending limits to prevent blocking or throttling.

Key considerations

  • SMTP Compliance: Understand and comply with SMTP server requirements to avoid rate limiting issues.
  • Reputation Monitoring: Regularly monitor your IP reputation using tools like Google Postmaster Tools and adjust sending practices as needed.
  • Microsoft Guidelines: Adhere to Microsoft's email sending limits and best practices to prevent deliverability issues.
Technical article

Documentation from Google Postmaster Tools explains the importance of maintaining a good IP reputation. Sending in batches allows you to monitor your reputation and make adjustments as needed, minimizing the risk of being flagged as spam.

July 2023 - Google
Technical article

Documentation from Microsoft outlines email sending limits and best practices. Sending in batches can help adhere to these limits and prevent your emails from being blocked or throttled.

June 2021 - Microsoft
Technical article

Documentation from RFC explains that SMTP servers may implement rate limiting to prevent abuse. Sending in batches can help avoid triggering these limits, especially on shared IPs where multiple users share the same sending infrastructure.

March 2021 - RFC 5321