Should marketing and transactional emails be sent from separate IPs or subdomains?
Summary
What email marketers say9Marketer opinions
Email marketer from Reddit explains that separating marketing and transactional emails by subdomains is a good idea for larger companies. This helps them to protect against the risk of marketing sends impacting transactional sends.
Email marketer from Mailjet Blog explains that separating IP addresses for marketing and transactional emails helps maintain a good sender reputation. Transactional emails are critical and require a high level of deliverability, while marketing emails often have higher complaint rates.
Email marketer from ActiveCampaign Blog explains that using subdomains for different types of emails (marketing vs. transactional) helps segment your sending reputation. This means that if your marketing emails have deliverability issues, it's less likely to affect your transactional emails.
Email marketer from Email on Acid explains the use of a subdomain as a key element of sender reputation protection. It allows segmentation and allows for better brand reputation management overall, it also provides clarity for recipients.
Email marketer from Email Marketing Forum shares that using a dedicated IP is best for transactional emails but that for marketing email shared IPs can be more cost effective
Marketer from Email Geeks shares examples of clients successfully sending both commercial and transactional emails from one IP using the same sending domain.
Email marketer from StackOverflow shares that transactional and marketing emails should be separated at the IP level. This protects the sender rating on transactional emails, but marketing emails should not impact that.
Email marketer from SMTP2GO shares a blog post that details the need for separate sender reputations. If these are combined you risk the reputation of one damaging the other.
Email marketer from SendGrid Blog shares that while not always necessary, separating marketing and transactional emails onto different subdomains or dedicated IPs is a recommended practice to safeguard deliverability. Transactional emails' reputation is critical, and separating them prevents marketing campaigns from negatively impacting them.
What the experts say4Expert opinions
Expert from Spam Resource explains that while not always mandatory, separating marketing and transactional email streams can protect your transactional email reputation. This is particularly important if your marketing practices aren't perfect or if you're sending high volumes.
Expert from Email Geeks explains that the separation of marketing and transactional emails on different IPs is a defensive practice, stemming from a lack of trust in obtaining proper recipient permission. If good processes are in place, separation isn't always necessary. Consumer ISPs are also better at filtering mail based on factors beyond IP address, reducing the need for separation.
Expert from Word to the Wise shares that when warming up a dedicated IP address, it's crucial to maintain consistent volume and engagement, and to separate different types of mailstreams (e.g. marketing and transactional). A lack of consistent volume or a bad practice in one stream can impact the overall IP reputation
Expert from Email Geeks shares that the minimum IP volume isn't as critical as it once was. Low-volume dedicated IPs can still establish and maintain a good reputation.
What the documentation says4Technical articles
Email marketer from Microsoft documentation describes that separating sender reputations via different IPs or Subdomains ensures a higher chance of getting your emails to the inbox. It also ensures that you are following email best practices.
Documentation from Google Postmaster Tools explains that they track reputation metrics for sending IPs. Maintaining a good IP reputation is critical for ensuring emails reach the inbox, and separation of email types can help manage this.
Documentation from SparkPost explains that using separate IP pools for different types of email (e.g., marketing vs. transactional) is a common practice to isolate reputation. This way, if one type of email encounters deliverability issues, it doesn't affect the deliverability of the other.
Documentation from Amazon SES explains that using a dedicated IP address allows you to control your sending reputation. They recommend that you monitor your reputation closely and follow best practices to maintain a good sending reputation, regardless of the type of email you send.