Why should I use a subdomain as my sending domain?

Learn what subdomains are and why they should be used as a dedicated sending domain for your emails. 

What is an email subdomain?

An email comes from a domain, or web address, shown after the @ symbol in the address. This is typically the "root" or main domain of the company.
(example@CityGro.com, or testing@PatchRetention.com)

Subdomains deliver emails from addresses under your root domain. Internet Service Providers (ISPs) and inboxes treat the subdomain differently even though it's connected to your root domain. i.e. testing@send.PatchRetention.com

How does having separate subdomains help?

Your email domain plays a big role in your sender reputation. Since they are one of the indicators of where a message is coming from, ISPs keep track of your domain reputation. 

Email subdomains are great for isolating variables since ISPs don't explain exactly how they decide whether a sender is trustworthy.

To track and manage reputation, you should create separate email subdomains within your email program.

It's less likely that a rise in spam complaints or a big swing in send volume will affect your root or subdomain if they're separate.

Don't let any email marketing mistakes get in the way of your root domain reputation, which can affect deliverability for PR, sales, or other team members who send personal or outreach emails from the root domain.

How many subdomains do I need?

You'd have multiple subdomains if you want to separate email types like promotional and transactional. You'd have one if you want to separate it from the root domain.

Does it work if I just send from different email addresses at the same domain?

If you change the name before the @ in an email address, that's not the same thing as using a subdomain. For example, marketing@widgets.com and help@widgets.com share the same domain.

Changing the names before the @ helps you organize your senders, but since it isn't actually a separate subdomain, sending activity from each person impacts the rest of the senders as well. Therefore, if you want to compartmentalize sending to protect deliverability, this won't work.

How do I set up a subdomain?

Email service providers (ESPs) have different instructions for setting up new email subdomains, so ask your account manager, support team, or the platform's help docs for more info.

For a complete walkthrough to add an email subdomain, click here.

Navigate to the Email Settings option from the Account Settings page.

In the ‘Email From Domains’ section, click on the (+)button in the lower right of that window to begin adding your new email domain.



It's important to keep best practices in mind:

1. Get the new subdomain set up with email authentication.
2. You need to warm up new subdomains just like new IPs because inbox providers see them as unknowns.
3. Include links to your root domain in your emails.
4. Rules should be set up for subdomain email addresses so replies come to a monitored inbox.
5. In case people type it in their browser, redirect subdomains to your root domain.