How to warm up email sending after a break to avoid spam filters?

Summary

Warming up email sending after a break is crucial for maintaining a positive sender reputation and avoiding spam filters. Experts and marketers recommend gradually increasing email volume, starting with engaged users, ensuring proper authentication (SPF, DKIM, DMARC), monitoring deliverability metrics, and addressing content/list quality. Resources like Google Postmaster Tools provide valuable insights into sender reputation.

Key findings

  • Gradual Volume Increase: Increase sending volume gradually to re-establish sender reputation.
  • Engaged Users First: Prioritize sending emails to your most engaged subscribers initially.
  • Proper Authentication: Ensure your email is properly authenticated using SPF, DKIM, and DMARC.
  • Monitor Metrics: Closely monitor deliverability metrics such as bounce rates and spam complaints.
  • Google Postmaster Tools: Utilize Google Postmaster Tools (GPT) for insights into your sending reputation and potential issues.
  • Address list and content quality: Ensure your sending list is of high quality and that your email content is of sufficient quality

Key considerations

  • List Segmentation: Segment your email list to target specific groups with relevant content and identify engaged users.
  • Content Quality: Ensure your email content is valuable, relevant, and avoids spam triggers.
  • ESP Limits: Be mindful of sending limits imposed by your Email Service Provider (ESP).
  • Consistency: Maintain consistent sending patterns once the warm-up is complete.
  • Inactivity Impact: Acknowledge and address the negative impact of inactivity on sender reputation.
  • Testing: Test your email sending configuration and content before and during the warm-up process.
  • IP type: If your sending on a new IP then the warm-up process should be followed very carefully

What email marketers say
11Marketer opinions

Warming up email sending after a break involves gradually increasing the volume of emails sent to re-establish a positive sender reputation with ISPs and avoid spam filters. This includes identifying and sending to your most engaged users first, ensuring proper email authentication (SPF, DKIM, DMARC), monitoring deliverability metrics (bounce rates, spam complaints), and reviewing Google Postmaster Tools for any changes in reputation or errors. It's also crucial to determine any underlying issues causing changes in inbox placement by testing production content and plain templates.

Key opinions

  • Gradual Increase: Gradually increase the volume of emails sent over time.
  • Engaged Users: Start by sending to your most engaged users (those who regularly open emails or click links).
  • Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is in place.
  • Monitoring: Monitor deliverability metrics such as bounce rates and spam complaints.
  • Content Review: Review content to ensure it adheres to best practices and doesn't trigger spam filters.
  • Google Postmaster Tools: Regularly check Google Postmaster Tools (GPT) for insights into your sender reputation.

Key considerations

  • Content Quality: Ensure content is valuable and relevant to recipients.
  • List Segmentation: Segment your email list and target specific groups with tailored content.
  • ESP Limits: Be aware of email sending limits set by your Email Service Provider (ESP).
  • Inactivity Impact: Acknowledge that periods of inactivity can negatively impact sender reputation.
  • Testing: Perform inbox placement tests using seed lists and third-party tools.
  • Deliverability Change: Test production content and plain templates to identify deliverability changes.
Marketer view

Email marketer from ActiveCampaign Blog shares that warming up an IP includes maintaining consistent sending volume, authenticating your emails (SPF, DKIM, DMARC), and monitoring bounce rates and spam complaints.

November 2023 - ActiveCampaign Blog
Marketer view

Email marketer from EmailDeliverability.com advises warming up a new IP slowly over several weeks, starting with low volumes and sending to engaged users. Monitor your reputation closely.

December 2021 - EmailDeliverability.com
Marketer view

Email marketer from Reddit explains that to warm up your IP address, start sending small amounts of emails to your most engaged users, such as those who regularly open your emails or click links in them, and gradually increase the sending volume to avoid triggering spam filters.

June 2024 - Reddit
Marketer view

Marketer from Email Geeks suggests determining why there's a change in inbox placement by testing with internal seeds and a 3rd party service. Test both production content and a plain template to find underlying issues and review Google Postmaster Tools (GPT) for changes in reputation, errors, and authentication.

March 2024 - Email Geeks
Marketer view

Email marketer from Woodpecker.co Blog advises that you need to be aware of the email sending limits set by your ESP. Also, create different email sequences and gradually add recipients to each sequence.

May 2022 - Woodpecker.co Blog
Marketer view

Marketer from Email Geeks shares that if improving content and the email list aren't working, slowly reintroduce the email stream to Google domains.

August 2024 - Email Geeks
Marketer view

Email marketer from Mailjet Blog explains that warming up an IP address involves gradually increasing the volume of emails sent over a period of time to establish a positive sender reputation with ISPs. Start with small volumes and gradually increase it.

December 2021 - Mailjet Blog
Marketer view

Email marketer from GlockApps Blog details a warm-up schedule, suggesting starting with 50 emails per day and increasing gradually, monitoring deliverability at each stage. They also stress the importance of having proper authentication in place.

April 2024 - GlockApps Blog
Marketer view

Email marketer from SendGrid Blog shares that warming up an IP involves progressively increasing sending volume to build a good reputation. Start with your most engaged users and monitor deliverability closely.

July 2022 - SendGrid Blog
Marketer view

Email marketer from Litmus Blog shares that warming up is essential for new IPs and domains, and after a period of inactivity. It builds sender reputation, ensuring emails reach inboxes. Proper setup and authentication are key.

February 2022 - Litmus Blog
Marketer view

Email marketer from MailerLite Blog explains that a warm-up process is vital to ensure emails arrive in the recipient's inbox and not the spam folder. Gradually build a positive reputation by increasing volume each day. Start with subscribers who have recently interacted with your emails.

December 2024 - MailerLite Blog

What the experts say
2Expert opinions

After a period of email sending inactivity, experts emphasize the importance of IP warming to maintain a positive sender reputation and avoid spam filters. A gradual ramp-up, sending initially to smaller, more engaged segments, is crucial.

Key opinions

  • IP Warming is Essential: IP warming is essential after periods of inactivity.
  • Gradual Ramp-Up: A gradual ramp-up of sending volume is crucial for re-establishing a positive reputation.
  • Engaged Segments: Start by sending to smaller, more engaged segments of your email list.
  • Monitor Metrics: Monitoring key email delivery metrics is important to avoid spam filters.

Key considerations

  • List Segmentation: Proper list segmentation is necessary for identifying engaged recipients.
  • Reputation Impact: Understand that inactivity affects sender reputation and requires a strategic recovery.
  • Ramp-Up Speed: Determine an appropriate pace for gradually increasing email volume based on engagement.
Expert view

Expert from SpamResource explains that after a period of inactivity, IP warming is essential. Start with your most engaged recipients and monitor key metrics to avoid filters.

January 2023 - SpamResource
Expert view

Expert from Word to the Wise shares that a gradual ramp-up when starting a new email program or resuming after a break helps establish a positive sending reputation. Send to smaller, more engaged segments first.

September 2021 - Word to the Wise

What the documentation says
3Technical articles

Official documentation from Google, Microsoft, and SparkPost emphasizes the importance of a gradual warm-up process when starting email sending on new IPs or after a break to maintain a good sender reputation. This involves starting with low volumes, increasing steadily, and focusing on sending to engaged subscribers initially.

Key findings

  • Gradual Increase: Gradually increase email volume to avoid negative impact on sender reputation.
  • Low Volume Start: Begin with sending small amounts of mail.
  • Monitor Reputation: Monitor your IP's reputation throughout the warm-up process.
  • Engaged Subscribers First: Prioritize sending to your most engaged subscribers during the warm-up.

Key considerations

  • Segmentation: Segment your lists to identify and target engaged subscribers effectively.
  • IP Type: Understand that new or newly dedicated IPs particularly require a warm-up period.
  • Engagement Metrics: Use engagement metrics to inform your warm-up strategy and volume increases.
Technical article

Documentation from Google Postmaster Tools Help explains that if you start sending a high volume of emails suddenly, it can impact your sender reputation. They recommend gradually increasing the volume of email you send.

September 2021 - Google Postmaster Tools Help
Technical article

Documentation from Microsoft explains that newly dedicated IPs require a warm-up period. Start with sending small amounts of mail and gradually increase to your intended volume, while also monitoring the IP's reputation.

March 2022 - Microsoft Documentation
Technical article

Documentation from SparkPost suggests starting with low volume and steadily increasing based on positive engagement. They advise segmenting your lists and sending to your most engaged subscribers first during the warm-up process.

April 2022 - SparkPost Documentation