What are the best practices for switching to a new sending domain?

Summary

When switching to a new sending domain, a comprehensive approach is crucial, encompassing technical configurations, careful planning, and continuous monitoring. Treat the new domain as entirely new to ISPs, requiring a warm-up period. Implement SPF, DKIM, and DMARC for authentication and to prevent spoofing. Start by gradually increasing the email volume, focusing first on engaged subscribers. Continuously monitor your sender reputation, bounce rates, spam complaints, and inbox placement using seedlists. Ensure a clean and engaged subscriber list to minimize bounces and spam complaints. Avoid switching IPs simultaneously and maintain consistent sending volumes. Utilize a subdomain for marketing emails. Review email content to avoid spam trigger words and test across various email clients. Establish feedback loops with ISPs, encourage subscribers to whitelist your new address, and adhere to a controlled sending schedule for IP warming to build a positive reputation with ISPs.

Key findings

  • Treat as New Domain: ISPs will treat the new sending domain as entirely new, requiring a warm-up period.
  • Authentication (SPF, DKIM, DMARC): Implement SPF, DKIM, and DMARC to authenticate emails and prevent spoofing.
  • Gradual Warm-Up: Gradually increase sending volume, starting with engaged subscribers.
  • Monitor Sender Reputation: Closely monitor sender reputation, bounce rates, and spam complaints.
  • Clean Subscriber List: Maintain a clean and engaged subscriber list to minimize bounces and spam complaints.
  • Avoid Simultaneous IP Change: Avoid changing IPs at the same time as switching domains.
  • Consistent Sending Volume: Maintain consistent sending volumes to build trust with ISPs.
  • Subdomain Usage: Consider using a subdomain for marketing emails.
  • Avoid Spam Trigger Words: Avoid using spam trigger words in email content.
  • Email Testing: Test email content across different clients.
  • Feedback Loops: Establish feedback loops with ISPs.
  • Subscriber Whitelisting: Encourage subscribers to whitelist the new address.
  • Seedlist Monitoring: Regularly monitor inbox placement with seedlists

Key considerations

  • ISP Perspective: Understand how ISPs view new sending domains and their associated risks.
  • Technical Setup Complexity: Proper configuration of SPF, DKIM, and DMARC requires technical expertise.
  • Warm-Up Patience: The warm-up process is gradual and requires patience to build a strong sending reputation.
  • Data Quality Impact: The quality of your email list directly affects deliverability.
  • Monitoring Responsiveness: Be prepared to address deliverability issues promptly based on monitoring data.
  • Reputation Building is Key: Reputation is everything, so focus on building a positive one

What email marketers say
9Marketer opinions

When switching to a new sending domain, a multi-faceted approach is essential to ensure deliverability and maintain a positive sender reputation. This involves careful monitoring, gradual volume increases, strategic list segmentation, and technical configurations. It is important to monitor sender reputation using tools to track sender score, bounce rates, and spam complaints. Gradually increase sending volume to avoid triggering spam filters and segment email lists, targeting engaged subscribers first. Employ a subdomain to isolate marketing traffic, avoid spam trigger words in email content, and establish feedback loops with ISPs. Encourage subscribers to whitelist the new address, and test email content across different clients to optimize user experience. Proper warm-up of the new domain and IP, combined with cleaning up email lists is essential.

Key opinions

  • Monitor Reputation: Closely monitor sender reputation using tools to track sender score, bounce rates, and spam complaints.
  • Gradual Volume Increase: Gradually increase sending volume to avoid triggering spam filters and damaging reputation.
  • List Segmentation: Segment email lists, targeting engaged subscribers first to demonstrate positive engagement.
  • Subdomain Isolation: Consider using a subdomain for marketing emails to isolate traffic and protect domain reputation.
  • Avoid Spam Triggers: Avoid using spam trigger words in email content and subject lines.
  • Feedback Loops: Set up feedback loops with ISPs to receive notifications about spam complaints.
  • Whitelisting: Encourage subscribers to add the new sending address to their address book or whitelist it.
  • Email Testing: Test email content across different clients and devices for optimal rendering and user experience.
  • Clean Email List: Keep email lists clean, with verified and engaged subscribers to minimise bounces and spam complaints.
  • Domain/IP Warming: Warm up a new sending IP and domain by starting with small volumes and gradually increasing them.

Key considerations

  • Reputation Management: Continuously monitor and manage sender reputation as the new domain is used.
  • Deliverability Impact: Understand that poor practices can negatively impact deliverability.
  • Subscriber Engagement: Prioritize engagement with active subscribers to demonstrate positive metrics.
  • Technical Setup: Ensure correct authentication setup (SPF, DKIM, DMARC) for the new domain.
  • Content Quality: Maintain high content quality and relevance to avoid spam complaints.
Marketer view

Email marketer from Mailjet explains that it's crucial to gradually increase your sending volume when using a new domain. Avoid sending large volumes of emails all at once, as this can trigger spam filters and damage your reputation. Start with smaller, targeted campaigns and gradually scale up.

February 2023 - Mailjet
Marketer view

Email marketer from HubSpot explains that you should set up feedback loops with major ISPs to receive notifications about spam complaints. This allows you to quickly identify and address any issues that may be affecting your deliverability.

August 2021 - HubSpot
Marketer view

Email marketer from Email on Acid explains that segmenting your email list is essential for warming up a new domain. Send emails to your most engaged subscribers first to demonstrate positive engagement to ISPs and improve your sender reputation.

July 2024 - Email on Acid
Marketer view

Email marketer from ActiveCampaign shares that it can be helpful to ask subscribers to add your new sending address to their address book or whitelist it with their email provider. This indicates to ISPs that your emails are wanted and can improve deliverability.

April 2023 - ActiveCampaign
Marketer view

Email marketer from SendGrid explains that you should closely monitor your sending reputation when switching to a new domain. Use tools to track your sender score, bounce rates, and spam complaints to identify and address any issues promptly.

November 2023 - SendGrid
Marketer view

Email marketer from Litmus highlights the importance of testing email content across different email clients and devices to ensure optimal rendering and user experience, which can impact engagement metrics and sender reputation.

May 2024 - Litmus
Marketer view

Email marketer from GMass shares that consider using a subdomain for your marketing emails. This isolates your marketing traffic from your transactional emails, protecting your primary domain's reputation.

July 2024 - GMass
Marketer view

Email marketer from Reddit user u/EmailPro shares that maintaining consistent sending volumes helps build trust with ISPs. Avoid large fluctuations in your sending patterns, as this can raise red flags and impact deliverability.

July 2023 - Reddit
Marketer view

Email marketer from Email Marketing Forum shares that it's very important to avoid using spam trigger words in your email content and subject lines. Words like "free," "guarantee," and "urgent" can increase the likelihood of your emails being flagged as spam.

November 2023 - Email Marketing Forum

What the experts say
5Expert opinions

Switching to a new sending domain requires careful planning and execution. Experts emphasize the importance of treating the new domain as if it were entirely new to ISPs, meaning it requires a warm-up period. It's advisable to avoid changing IPs simultaneously. Gradual ramping up of email volume is essential, and one should avoid switching all email uses at once. Using seedlists to monitor inbox placement before sending to real subscribers is recommended to identify deliverability problems early. A clean, engaged subscriber list is crucial to minimize bounces and spam complaints. A gradual warm-up process for both IP and domain, coupled with continuous monitoring of deliverability results, will help build a positive reputation with ISPs.

Key opinions

  • Treat as New: ISPs will treat a new sending domain as entirely new, so expect deliverability challenges.
  • Avoid Simultaneous IP Change: Avoid changing IPs at the same time as switching domains.
  • Gradual Ramp-Up: Ramp up email volume gradually, and don't switch all uses to the new domain at once.
  • Seedlist Testing: Use seedlists to check inbox placement before sending to real subscribers.
  • List Hygiene: Maintain a clean, engaged subscriber list to minimize bounces and spam complaints.
  • Domain/IP Warming: Warm up the new sending IP and domain with small volumes and gradual increases.
  • Monitor Results: Continuously monitor deliverability results throughout the warm-up process.

Key considerations

  • ISP Perspective: Understand that ISPs will initially view the new domain with suspicion.
  • Patience: The warm-up process takes time and requires patience.
  • Data Quality: The quality of your email list significantly impacts deliverability on a new domain.
  • Monitoring: Close monitoring is critical to catch and address any deliverability issues early.
  • Gradual Transition: A gradual and controlled transition minimizes the risk of deliverability problems.
Expert view

Expert from SpamResource recommends using a seedlist to check your inbox placement before sending to real subscribers. This helps identify potential deliverability issues early on. This should be done regularly and especially when migrating to a new sending domain.

September 2021 - SpamResource
Expert view

Expert from SpamResource explains that a key best practice is to ensure your lists are clean, with verified and engaged subscribers, before using a new sending domain. This minimises bounces and spam complaints from inactive users.

May 2022 - SpamResource
Expert view

Expert from Word to the Wise highlights the significance of properly warming up a new sending IP and domain by starting with small volumes and gradually increasing them. They emphasize the importance of monitoring the results to ensure good deliverability. This gradual approach is crucial for building a positive reputation with ISPs.

March 2022 - Word to the Wise
Expert view

Expert from Email Geeks explains that as far as the ISP is concerned, a new domain will have issues. He suggests to not switch IPs at the same time and to warm up traffic to the new domain.

March 2024 - Email Geeks
Expert view

Expert from Email Geeks shares that you'll definitely want to ramp things up carefully and maybe not switch all your uses over at the same time when switching to a new sending domain.

October 2022 - Email Geeks

What the documentation says
5Technical articles

When switching to a new sending domain, it is crucial to follow email authentication and warm-up best practices. This includes gradually increasing the volume of emails sent, starting with engaged users, and closely monitoring deliverability. Essential technical configurations include setting up SPF, DKIM, and DMARC records to verify email authenticity and prevent spoofing. A controlled sending schedule is recommended for IP warming to build a positive reputation with ISPs.

Key findings

  • IP Warm-up: Gradually increase sending volume to warm up the IP address, starting with engaged users.
  • SPF Record: Set up a Sender Policy Framework (SPF) record for the new sending domain to authorize sending servers.
  • DKIM Configuration: Configure DomainKeys Identified Mail (DKIM) for the new sending domain to add a digital signature to emails.
  • DMARC Policy: Implement a Domain-based Message Authentication, Reporting & Conformance (DMARC) policy for the new sending domain to protect against spoofing and phishing attacks.
  • Controlled Schedule: Use a controlled sending schedule for IP warming to build a positive reputation.

Key considerations

  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is crucial for establishing trust with receiving mail servers.
  • Gradual Increase: Avoid sending large volumes of emails immediately to prevent being flagged as spam.
  • Monitoring: Continuously monitor deliverability metrics during the warm-up process.
  • Engaged Users: Start by sending emails to highly engaged users to build a positive sending reputation.
  • Reputation Building: The IP and domain warm-up process is essential for establishing a positive sender reputation with ISPs.
Technical article

Documentation from DMARC.org shares that you should implement Domain-based Message Authentication, Reporting & Conformance (DMARC) policy for your new sending domain to protect against email spoofing and phishing attacks. DMARC builds upon SPF and DKIM to provide a comprehensive email authentication framework.

March 2025 - DMARC.org
Technical article

Documentation from Microsoft shares that you should configure DomainKeys Identified Mail (DKIM) for your new sending domain. DKIM adds a digital signature to your emails, allowing recipient servers to verify the authenticity of your messages and prevent spoofing.

February 2022 - Microsoft
Technical article

Documentation from Google explains that when setting up a new sending domain, you should warm up your IP address by gradually increasing the volume of emails sent. Start with small batches to engaged users and slowly increase the volume while monitoring deliverability.

October 2023 - Google
Technical article

Documentation from SparkPost details an approach to IP warming using a controlled sending schedule to build a positive reputation with ISPs over time.

August 2022 - SparkPost
Technical article

Documentation from RFC-Editor explains that a Sender Policy Framework (SPF) record should be set up for your new sending domain. This helps receiving mail servers verify that emails coming from your domain are authorized, improving deliverability.

August 2024 - RFC-Editor