Summary
Email marketers, experts, and documentation from ESPs and inbox providers overwhelmingly recommend using separate subdomains (or even domains and IPs) for marketing and transactional emails. This strategy protects the primary domain's reputation by isolating deliverability issues. It also allows for segmented monitoring, improved email classification by ISPs, distinct authentication methods, and dedicated feedback loops. Sufficient email volume in both categories is a consideration, as the definition of 'sufficient' varies by target domain.
Key findings
- Reputation Isolation: Using separate subdomains isolates the reputation of marketing and transactional emails, preventing issues in one stream from impacting the other.
- Primary Domain Protection: Separate subdomains protect the main domain's reputation, particularly ensuring critical transactional emails are not affected by marketing campaigns.
- Segmented Monitoring: Using subdomains allows for separate performance monitoring and targeted troubleshooting of deliverability issues specific to each email type.
- ISP Classification: Different subdomains may assist ISPs in classifying emails into the appropriate inbox folders.
- Distinct Authentication: Enables the use of different authentication methods (like DKIM) for each type of email.
Key considerations
- Sufficient Volume: Sufficient email volume in both marketing and transactional streams is needed to justify separate subdomains; the definition of 'sufficient' depends on the target domain.
- Implementation Complexity: Setting up and managing separate subdomains (or domains/IPs) requires more technical expertise and resources.
- Dedicated Feedback Loops: Requires managing dedicated feedback loops and suppression lists for each stream.
What email marketers say
14 marketer opinions
The consensus among email marketers and experts is that using separate subdomains for marketing and transactional emails is highly recommended. This practice isolates sender reputation, protects main domain health, allows for segmented performance monitoring, and helps in classifying email types appropriately by ISPs. Sufficient volume is needed to justify subdomain separation, with the amount varying based on the target domain.
Key opinions
- Reputation Isolation: Separate subdomains isolate the reputation of marketing and transactional emails, preventing issues with one from affecting the other.
- Main Domain Protection: Using subdomains protects the main domain's reputation, ensuring critical transactional emails remain unaffected by marketing campaign deliverability issues.
- Segmented Monitoring: Subdomains enable segmented performance monitoring, allowing for targeted troubleshooting of deliverability issues specific to each email type.
- ISP Classification: Separate subdomains can assist ISPs in classifying emails into appropriate inbox folders, improving overall deliverability.
Key considerations
- Sufficient Volume: Sufficient email volume in both marketing and transactional streams is necessary to justify the use of separate subdomains.
- Target Domain: The definition of 'sufficient volume' is dependent on the target domain and its reputation requirements.
- DKIM signing: Use DKIM signing when implementing subdomains.
Marketer view
Marketer from Email Geeks recommends that, assuming sufficient volume in both, its 100% recommended.
13 May 2024 - Email Geeks
Marketer view
Email marketer from Mailgun Blog explains that using subdomains for different types of emails (marketing vs. transactional) helps isolate reputation. If your marketing emails have deliverability issues, it won't affect your transactional emails.
14 Sep 2024 - Mailgun Blog
What the experts say
2 expert opinions
Experts recommend using separate subdomains (or even separate domains and IPs) for marketing and transactional emails. This allows for distinct authentication methods and the use of dedicated feedback loops and suppression lists. The primary goal is to isolate transactional emails, ensuring their reliable delivery.
Key opinions
- Isolation: Separating email types by subdomain/domain isolates transactional sends, ensuring they are not impacted by marketing campaigns.
- Different IPs & Authentication: Using separate subdomains or domains facilitates the use of different IPs and authentication methods for different email types.
- Dedicated Feedback Loops: Segmentation allows the use of dedicated feedback loops and suppression lists for each email type.
Key considerations
- Implementation Complexity: Implementing separate subdomains/domains and IPs requires more complex setup and management.
- Resource Allocation: Consider the resources needed to manage and monitor multiple sending infrastructures.
Expert view
Expert from Spamresource explains that many companies use different subdomains for different classes of mail, for example transactional vs marketing. This allows the business to send from different IPs and use different authentication for different classes of mail.
24 Sep 2023 - Spamresource
Expert view
Expert from Word to the Wise advises using separate IPs and domains to handle marketing vs transactional emails and implement dedicated feedback loops and suppression lists. This isolates your transactional sends, which must get through.
21 Jul 2021 - Word to the Wise
What the documentation says
4 technical articles
Email service providers (SendGrid, SparkPost) and inbox providers (Google, Microsoft) documentation recommends separating email streams, using either separate subdomains or domains, for marketing and transactional emails. This protects the primary domain's reputation, improves deliverability, isolates deliverability issues, and ensures the reliability of transactional emails.
Key findings
- Reputation Protection: Separate sending domains/subdomains protect the primary domain's reputation.
- Improved Deliverability: Separation improves email deliverability overall.
- Issue Isolation: Separating email streams isolates deliverability issues.
- Transactional Reliability: Ensures the reliability of transactional emails.
Key considerations
- Setup Complexity: Setting up and managing separate subdomains/domains requires technical expertise.
- Domain Management: Consider the effort needed to manage multiple domains/subdomains and their authentication.
Technical article
Documentation from SparkPost Documentation suggests separating sending domains or subdomains for different email streams as a best practice for managing sender reputation and improving deliverability. This is particularly useful for isolating transactional emails from marketing campaigns.
26 Aug 2021 - SparkPost Documentation
Technical article
Documentation from Microsoft recommends to use different domains for different purposes, like transactional and marketing. This ensures that any deliverability issues with marketing won't affect the reliability of transactional emails.
13 Aug 2021 - Microsoft
Should I use separate email subdomains for transactional and promotional emails, and how does engagement affect this?
Should I use separate IPs or domains for transactional vs marketing emails?
Should I use subdomains for transactional and promotional emails to protect my main domain reputation?
Should marketing and transactional emails be sent from separate IPs or subdomains?
Should transactional emails have separate authentication from bulk emails?
Should transactional emails include an unsubscribe link and how should you handle incorrect email addresses?
