Can I use the same subdomain for multiple email sending platforms?

Email marketer from Email on Acid mentions it's best to use a separate subdomain for testing various email campaigns, especially when involving different email platforms. This is to ensure that your main sending domain's reputation remains untainted during the testing phase.

Email marketer from Mailjet responds that sharing a subdomain across multiple ESPs can negatively affect your sender reputation if one ESP has poor sending practices. Isolating each ESP with its own subdomain is a safer approach.

Email marketer from Litmus shares that a sound strategy to consider is using separate subdomains for different types of email traffic to help segment and manage your sender reputation more effectively, particularly useful when employing multiple email sending platforms.

Email marketer from SuperOffice suggests that it's safer to have separate subdomains because it offers you more control and reduces the risk of one platform's sending reputation impacting the deliverability of emails sent from another.

Email marketer from Reddit responds that they strongly advise against using the same subdomain across multiple email marketing platforms. The risk of deliverability issues and reputation damage is too high.

Marketer from Email Geeks shares that using your own domains for authentication often requires the use of CNAMEs or specific TXT records to exist at specific places in your DNS.

Email marketer from StackOverflow explains that it's feasible to share a subdomain but warns of complexities in managing SPF records. It also advises that it is necessary to monitor and actively manage the reputation for each platform using that subdomain.

Marketer from Email Geeks explains that Marketo likely has you add a CNAME that points to their DKIM key, or to their MX record or their SPF record, and CrowdTech could require you to add a CNAME that points to their keys and records.

Email marketer from SendGrid shares that using dedicated sending domains or subdomains for each email stream helps protect your sender reputation. This isolation prevents one platform's issues from impacting others.

Email marketer from Neil Patel Blog explains that while it's technically possible to use the same subdomain, it's generally not recommended due to deliverability and reputation concerns. Each platform should ideally have its own subdomain to isolate any potential issues.

Expert from Email Geeks explains that it is poor practice to share subdomains across different mailing companies because of the high chance of messing something up, and that the overhead to prevent this is more than setting up an independent subdomain for each vendor.

Expert from Word to the Wise responds that sender reputation is tied to the domain, and that it is advisable to separate sending based on the type of mail you are sending. Using different subdomains for each can help maintain good reputations of the individual subdomain.

Expert from Spam Resource explains that subdomains can be used to separate your sending streams for different types of mail such as marketing vs transactional emails, and for different companies, it is better to separate them out to protect your reputation.

Expert from Email Geeks responds that setting up an independent subdomain is just creating the domain and setting up the DNS records.

Expert from Email Geeks shares her biggest concern would be bounce handling, and asks what the process is for getting bounces back to the sending server for suppression.

Documentation from RFC explains that SPF records have limitations on the number of DNS lookups, making it difficult to authorize multiple third-party senders on a single domain or subdomain without exceeding these limits.

Documentation from Google Workspace advises that bulk senders should authenticate their email with SPF and DKIM. Using separate subdomains for different types of email can help manage reputation and deliverability.

Documentation from Microsoft clarifies that when using multiple email platforms for different marketing initiatives, they encourage using a unique subdomain. This strategy allows more control over authentication configurations and easier monitoring.

Documentation from DMARC.org explains that subdomains can inherit the DMARC policy of the parent domain, but proper alignment (SPF and DKIM) is crucial for DMARC to pass. Using different ESPs on the same subdomain can complicate DMARC alignment.

Documentation from AWS suggests that a best practice is to configure unique subdomains for different types of email traffic. This includes separating transactional email from marketing communications, especially when leveraging different ESPs for each.