What checklist of things to check when switching from sending emails from a primary domain to a subdomain?
Summary
What email marketers say10Marketer opinions
Email marketer from Litmus says to use a DNS record checker to verify that your SPF, DKIM, and DMARC records are correctly configured for the subdomain. This ensures that your email authentication settings are properly implemented and can help prevent deliverability issues.
Email marketer from Email Geeks says it's a good idea to make it obvious what the stream is for by using separate subdomains.
Email marketer from SendGrid explains that focus on engaging your subscribers by sending relevant and valuable content. Encourage recipients to interact with your emails by including clear calls-to-action and providing opportunities for feedback. High engagement rates can improve your sender reputation and deliverability.
Email marketer from Mailjet explains that warming up the subdomain is critical. Start by sending low volumes of email and gradually increase over time. Monitor your sender reputation and deliverability metrics closely during the warmup period to identify and address any issues promptly. This allows mailbox providers to learn the legitimacy of the new subdomain.
Email marketer from Quora shares the advice to maintain good email list hygiene by regularly removing inactive subscribers and validating email addresses. This helps reduce bounce rates and improve overall deliverability, ensuring that your emails reach engaged recipients.
Email marketer from GMass recommends sending test emails to different email providers (Gmail, Yahoo, Outlook, etc.) to check for deliverability issues and rendering problems. Analyze the headers of the test emails to identify any potential authentication or configuration issues. The URL explains more about GMass services.
Email marketer from Email On Acid answers says to review your email content to ensure it complies with email marketing best practices and avoids spam triggers. Optimize subject lines, body copy, and images to improve engagement and reduce the likelihood of being flagged as spam. Test your email rendering to ensure it displays properly across different email clients and devices.
Email marketer from Reddit explains that if you are also changing your IP address, implement a proper IP warmup strategy alongside the subdomain warmup. Gradually increase sending volume from the new IP address to establish a positive reputation with mailbox providers. If you are not changing your IP, this can be skipped.
Email marketer from StackOverflow recommends setting up feedback loops with major mailbox providers like Gmail, Yahoo, and Outlook. This allows you to receive notifications about spam complaints, enabling you to promptly address any issues and maintain a positive sender reputation. This would be useful if deliverability problems are experienced.
Email marketer from SparkPost explains that continuously monitor your sender reputation and deliverability metrics using tools like Google Postmaster Tools and Sender Score. Pay attention to bounce rates, spam complaints, and engagement metrics to identify and address any deliverability issues proactively. The URL provides information on SparkPost's services.
What the experts say5Expert opinions
Expert from Spam Resource explains that when switching to a subdomain, it is crucial to ensure that the subdomain is properly configured within your email sending platform. Verify that the subdomain is correctly set up for sending emails and that all necessary configurations, such as authentication settings, are in place. Check that your email sending platform recognizes the new subdomain and can send emails on its behalf.
Expert from Email Geeks explains DKIM signing order. In header order (top down as reading headers): known signature then new signature. In signing order (so as you sign the outbound message): new signature than known signature. After a while you can switch them so it’s (header order) new signature then known signature. Then you can drop the old signature.
Expert from Word to the Wise shares the advice that they recommend different approaches to subdomains depending on the specific situation. She talks through when it's useful to change the HELO domain and when to keep it the same and how these decisions can influence sending reputation.
Expert from Email Geeks explains that you need to warmup the subdomain, but it doesn’t have to be a long warmup. They suggest adding a second DKIM signature with the domain to warmup for a while to introduce the domain and get the machine learning filters used to seeing it before it’s the identity that reputation is hung off of.
Expert from Email Geeks says that in general separate subdomains is preferred, but in some cases it’s not really necessary, it depends on volumes and deliverability concerns.
What the documentation says4Technical articles
Documentation from Google Workspace Admin Help explains that you need to update your SPF records to include the subdomain. This involves adding the subdomain to the existing SPF record or creating a new SPF record specifically for the subdomain. Ensure the SPF record accurately reflects the sending sources for the subdomain to avoid deliverability issues. The URL provided explains more on using SPF records.
Documentation from RFC standard explains that verify that your reverse DNS (PTR) record is properly configured for the sending IP address. The PTR record should match the hostname of your sending server, helping to establish trust with email receivers. More information on reverse DNS can be found via the link.
Documentation from Microsoft 365 documentation explains that when switching to a subdomain, generate a new DKIM record for the subdomain and publish it in the subdomain's DNS settings. Ensure that the sending server is configured to sign emails using the new DKIM key. Validate the DKIM configuration to confirm that emails are being signed correctly. The URL provides information on DKIM.
Documentation from DMARC.org explains that update your DMARC record to include the subdomain. This might involve creating a separate DMARC record for the subdomain or modifying the existing one to cover the new sending domain. Ensure the DMARC policy aligns with your sending practices for the subdomain, specifying how email receivers should handle emails that fail SPF and DKIM checks. See URL to learn more about DMARC.