How do you warm up a subdomain for email sending?

Summary

Warming up a subdomain for email sending is a multi-faceted process that requires a strategic approach to building a positive sender reputation. The core principle involves gradually increasing email volume, starting with your most engaged subscribers, and consistently monitoring deliverability metrics such as opens, clicks, bounces, and complaints. Email authentication (SPF, DKIM, DMARC) is paramount, and proper list management, including segmentation and opting-in processes, is crucial for maintaining a clean and engaged audience. The reputation of a subdomain can be independent of the parent domain, requiring careful monitoring. Key factors include content relevance, DNS record configuration, avoiding sudden volume spikes, and actively managing bounces and unsubscribes. The ultimate goal is to establish trust with mailbox providers and ensure that your emails reach the intended recipients' inboxes.

Key findings

  • Gradual Volume Increase: Gradually increase sending volume to build a positive reputation.
  • Engaged Subscribers: Start by sending to your most engaged subscribers.
  • Email Authentication: Implement and maintain SPF, DKIM, and DMARC for authentication.
  • Monitor Deliverability: Continuously monitor deliverability metrics (opens, clicks, bounces, complaints).
  • List Management: Practice good list management, including segmentation and opt-in processes.
  • Subdomain Reputation: Subdomain reputation can be independent of the parent domain, requiring careful monitoring.

Key considerations

  • Content Relevance: Ensure content is relevant and personalized to avoid spam complaints.
  • DNS Configuration: Correctly configure and monitor DNS records.
  • Avoid Sudden Spikes: Avoid sudden spikes in email volume, which can harm reputation.
  • Bounce Management: Actively manage bounces and unsubscribes to maintain a clean list.
  • Complaint Rates: Keep complaint rates low to protect your sender reputation.
  • Text to image ratio: Ensure email content has a good text to image ratio to avoid being flagged as spam.

What email marketers say
12Marketer opinions

Warming up a subdomain for email sending involves a gradual process focused on building a positive reputation with mailbox providers. Experts recommend starting with low sending volumes to your most engaged subscribers and gradually increasing the volume over time. Monitoring sender reputation and engagement metrics (opens, clicks, bounce rates, complaints) is crucial. Proper email authentication (SPF, DKIM, DMARC) is essential, and segmenting email lists based on engagement levels helps to ensure that the most active subscribers receive emails first. Some experts suggest that subdomain reputation is treated independently, so careful monitoring is important. Overall, a consistent sending schedule, relevant content, and proactive list management are key to a successful subdomain warm-up.

Key opinions

  • Gradual Ramp-Up: Start with low sending volumes and gradually increase over time.
  • Engaged Subscribers: Focus on sending to your most engaged subscribers initially.
  • Monitor Metrics: Monitor sender reputation, engagement metrics (opens, clicks), and bounce rates.
  • Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is configured.
  • Segmentation: Segment your email lists based on engagement levels.
  • Independent Reputation: Subdomain reputation may be treated independently from the parent domain.

Key considerations

  • Sending Volume: Avoid sudden spikes in email volume; increase gradually.
  • Content Relevance: Focus on relevant and personalized content to avoid spam complaints.
  • List Hygiene: Maintain a clean email list by managing bounces and unsubscribes.
  • Feedback Loops: Pay attention to feedback loops and react quickly to negative signals.
  • DNS Records: Ensure all DNS records are configured correctly and monitored.
  • Text to image ratio: Ensure a good text to image ratio to avoid being flagged as spam.
Marketer view

Marketer from Email Geeks suggests gradually changing out the domain while still using all the IPs, focusing on warming the domain rather than the IPs. No need to gradually use the IPs, just gradually use the domain.

October 2023 - Email Geeks
Marketer view

Marketer from Email Geeks shares their experience that root domain rep does not seem to carry to subdomain variations, as Google gives a different rep treatment for each sub even if they're on the same root.

November 2023 - Email Geeks

What the experts say
2Expert opinions

Warming up a subdomain requires careful attention to reputation, deliverability metrics, and list management. Experts emphasize the importance of sending to engaged subscribers and maintaining a clean email list. Monitoring deliverability metrics and segmenting sending based on engagement is crucial to ensure a smooth warm-up and protect overall domain reputation. Ensuring proper authentication such as SPF and DKIM is critical.

Key opinions

  • Separate Reputation: Subdomain reputation is often treated separately from the main domain.
  • Clean, Engaged List: Sending to a clean, engaged list is crucial during subdomain warm-up.
  • Double Opt-In: Using a double opt-in process helps ensure subscribers are genuinely interested.
  • Authentication is Key: Authentication with SPF and DKIM must be configured properly.

Key considerations

  • Monitoring Deliverability: Carefully monitor deliverability metrics.
  • Segmentation: Segment sending based on engagement.
  • List Hygiene: Actively manage bounces and unsubscribes to maintain list hygiene.
  • Avoid Spam Traps: Take steps to avoid spam traps.
Expert view

Expert from Spam Resource emphasizes that sending to a clean, engaged list is crucial during subdomain warm-up. He suggests using a double opt-in process to ensure subscribers are genuinely interested and actively managing bounces and unsubscribes to maintain list hygiene. This helps avoid spam traps and protects sender reputation.

June 2021 - Spam Resource
Expert view

Expert from Word to the Wise explains that subdomain reputation can be separate from the main domain. She recommends carefully monitoring deliverability metrics and segmenting sending based on engagement to ensure a smooth warm-up and protect overall domain reputation. Ensuring proper authentication like SPF and DKIM is crucial.

May 2024 - Word to the Wise

What the documentation says
3Technical articles

Warming up a subdomain for email sending, as detailed in various documentation sources, involves several key practices centered on establishing a positive sender reputation. Crucially, consistent email authentication (SPF, DKIM, DMARC) is paramount. Gradually increasing sending volumes, avoiding sudden spikes, and maintaining low complaint rates are essential. Best practices for list management, sending wanted mail, and monitoring reputation over time using available tools are also important.

Key findings

  • Email Authentication: Consistent authentication (SPF, DKIM, DMARC) is critical for establishing sender reputation.
  • Gradual Volume Increase: Warming up involves gradually increasing sending volumes to build trust.
  • Avoid Sudden Spikes: Sudden spikes in email volume can negatively impact sender reputation.

Key considerations

  • List Management: Adhere to best practices for list management to maintain a positive reputation.
  • Complaint Rates: Maintaining low complaint rates is crucial for avoiding deliverability issues.
  • SPF Record Setup: Properly formatted SPF records are essential for authentication.
  • Wanted Mail: Ensure you are sending mail that recipients want to receive.
  • Reputation Monitoring: Monitor your reputation over time using available tools.
Technical article

Documentation from Microsoft.com details that warming up a domain/subdomain involves gradually increasing sending volumes. Maintaining low complaint rates and adhering to best practices for email authentication and list management are crucial for building and maintaining a positive reputation.

June 2024 - Microsoft.com
Technical article

Documentation from RFC-Editor.org explains the setup of SPF records and importance of having a correctly formatted SPF record to assist with authentication. It is important to have your SPF setup correctly to ensure reputation.

March 2021 - RFC-Editor.org