Summary
Experts and marketers offer a range of perspectives on warming up a new tracking link when switching to a subdomain. Some suggest it's not strictly necessary, particularly if existing flows are naturally throttled, content filtering during the SMTP transaction is uncommon, and the sending domain is aligned. Others highlight the importance of warming up to build a positive sender reputation with ISPs, avoid being flagged as spam, and mitigate potential deliverability issues. Technical documentation emphasizes the need for proper SPF records and DKIM. The common thread is that monitoring deliverability metrics and sender reputation tools is crucial throughout the process, regardless of whether a full warmup is undertaken.
Key findings
- Mixed Opinions: There are mixed opinions on the necessity of warming up a new tracking subdomain.
- Sender Reputation: Establishing and maintaining a positive sender reputation is vital for deliverability.
- Authentication: Proper SPF records and DKIM are critical for authorizing sending servers.
- Gradual Increase: Gradually increasing email volume is recommended to avoid spam filters if warming up.
- Monitoring Crucial: Monitoring deliverability metrics and sender reputation is crucial regardless of warming up.
Key considerations
- Existing Flows: Consider whether existing email flows are already naturally throttled.
- Alignment: If the new subdomain aligns with the content, warming up may be less critical.
- Painful Warmup: If warming up is too difficult, switching may be a viable option with close monitoring.
- Deliverability Impact: Carefully consider the potential impact on spam filtering.
- Best Practices: Adhering to best practices for email authentication is essential.
- Reputation Damage: If you don't warm-up your new domain correctly, then you risk damaging your reputation
What email marketers say
7 marketer opinions
The consensus among email marketers and documentation suggests that warming up a new tracking link when switching to a subdomain is a recommended, albeit not always strictly necessary, best practice. Warming up involves gradually increasing traffic to the new subdomain to build a positive reputation with ISPs and avoid being flagged as spam. While some suggest it may not be critical if existing flows are naturally throttled, most agree that taking precautions can prevent deliverability issues. Monitoring deliverability metrics during the warmup period is consistently advised.
Key opinions
- Warming Recommended: Warming up a new tracking subdomain is generally recommended to establish trust with ISPs.
- Reputation Building: Gradually increasing traffic builds a positive reputation and avoids spam filters.
- Preventative Measure: Warming up acts as a preventative measure to avoid deliverability issues down the line.
- Gradual Increase: A gradual increase in email volume is key to a successful warm-up process.
- Monitoring: Consistent monitoring of deliverability metrics is crucial during the warm-up phase.
Key considerations
- Throttled Flows: If existing email flows are naturally throttled, warming up may be less critical but still beneficial.
- Engagement: Start by sending emails to your most engaged contacts during the warmup process.
- HTTPS Security: Ensure the new subdomain is secured with HTTPS.
- Aligning Content: Switching is easier if the subdomain aligns with the content you are sending.
- Reputation Damage: If you do not warm up your domain correctly, then you risk damaging your reputation
Marketer view
Email marketer from EmailVendorSelection shares the concept of warming up your IP and domain. They explain that ISPs establish your reputation based on your IP and domain. If you do not warm up your domain correctly, you could be flagged as a spammer. They advise that you gradually increase the number of emails you send.
3 Jul 2024 - EmailVendorSelection
Marketer view
Email marketer from Neil Patel's Blog explains that warming up a new subdomain for tracking links is similar to warming up a new IP address. It involves gradually increasing the volume of traffic to build a positive reputation and avoid being flagged as spam. Start with a small percentage of your email volume and slowly increase it over time.
23 Feb 2025 - Neil Patel's Blog
What the experts say
5 expert opinions
Experts offer varying perspectives on warming up a new tracking link when switching to a subdomain. Some suggest it's not essential, especially if content filtering during the SMTP transaction is uncommon and the sending domain is aligned. Rejections due to a new domain within the message are deemed unlikely by some. However, others recommend it as a good practice to improve sender reputation and mitigate potential spam filtering impacts. Monitoring results carefully is universally advised.
Key opinions
- Content Filtering: Most consumer domains don't content filter during the SMTP transaction.
- Rejections Unlikely: Rejections due to a new domain within the message are generally unlikely.
- Monitoring is Key: Careful monitoring of results is crucial for success.
- Improve Sender Reputation: Warming up the subdomain might improve your sender reputation.
- Easy to switch: If warming up is painful, you can switch it
Key considerations
- Painful Warmup: If warming up is too painful, just switch it, and problems will be obvious on the first send.
- Bounce Monitoring: Monitor for bounces immediately after the switch, as warmup won't help with bouncing issues.
- Impact on Spam Filtering: Consider how the change in tracking links could affect spam filtering.
- Aligned Sending: There's less need to be concerned if your sending is already aligned.
- Domain reputation: If you don't warm-up your new domain correctly, then you risk damaging your reputation
Expert view
Expert from Email Geeks explains that most places don’t content scan and reject after DATA (Yahoo being the obvious exception), so rejections due to a new domain inside the message are unlikely.
31 Oct 2023 - Email Geeks
Expert view
Expert from Email Geeks advises not to worry too much about warming up tracking links, but if it’s not too painful, it won’t hurt. If it is painful, just switch it. Problems will be obvious on the first send.
12 Nov 2022 - Email Geeks
What the documentation says
3 technical articles
Technical documentation from Google, Microsoft, and RFC Editor highlights the importance of sender reputation when using new subdomains for sending email. Google and Microsoft both advise a gradual increase in email volume to avoid being flagged as spam and recommend monitoring sender reputation tools. RFC Editor emphasizes the need for proper SPF records to authorize sending and improve deliverability, also highlighting the importance of DKIM.
Key findings
- Sender Reputation: Sender reputation is a critical factor in email deliverability, especially for new subdomains.
- Gradual Increase: Gradually increasing email volume is recommended to avoid being flagged as spam.
- Monitoring: Monitoring sender reputation tools is essential (e.g., Google Postmaster Tools, Microsoft SNDS).
- SPF Records: Properly configured SPF records are crucial for authorizing sending servers.
- DKIM Importance: Implementing DKIM is also important for improving deliverability
Key considerations
- Spam Flagging: Avoid sudden spikes in email volume that can lead to being flagged as spam.
- Authentication: Ensure SPF records authorize your sending servers to send on behalf of the new subdomain.
- Reputation Tools: Utilize sender reputation tools provided by mailbox providers to monitor deliverability.
- Domain Reputation: Consider the domain reputation before using
Technical article
Documentation from Microsoft 365 Defender mentions that sender reputation, including the reputation of domains and subdomains, is a critical factor in email deliverability. New subdomains should be warmed up gradually to establish a positive reputation and avoid being blocked by spam filters. Monitor your reputation using the Microsoft SNDS program.
22 Oct 2024 - Microsoft 365 Defender
Technical article
Documentation from RFC Editor explains that ensure your new tracking subdomain is properly configured with SPF records that authorize your sending servers to send email on behalf of that subdomain. Incorrect or missing SPF records can negatively impact deliverability. It is also important to set up DKIM.
5 Apr 2025 - RFC Editor
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