When setting up a branded sending domain, you’ll need to choose a subdomain (or prefix). This subdomain becomes part of the domain used to send your emails and plays an important role in organization, branding, and deliverability.
Branded sending subdomains are a part of your overall sending domain setup and play a role in how your emails are authenticated and delivered.
To understand how this fits into your broader setup, refer to "Branded vs. Shared Sending Domains: What’s the Difference?"
This guide explains what a sending subdomain is and how to choose the right one for your business.
What is a Sending Subdomain?
A sending domain is the domain your emails are sent from, and it appears in your email headers. A subdomain is the prefix added before your main domain.
For example:
If your sending domain is send.yourbusiness.com,
Then “send” is the subdomain.
You can choose almost any word as your subdomain, as long as it isn’t already being used in your DNS (Domain Name System).
How to Choose the Right Subdomain
While you have flexibility in naming your subdomain, it’s best to choose something that clearly reflects its purpose.
Common examples include:
send.yourdomain.com
email.yourdomain.com
newsletter.yourdomain.com
Using a clear and relevant prefix makes it easier to identify the purpose of the domain, especially when managing DNS records or working with teams.
Best Practices for Choosing a Sending Subdomain
1. Ensure the Subdomain is Unique
Each subdomain must be unique within your DNS. You cannot reuse the same subdomain for multiple purposes under the same domain.
Before selecting one, check your DNS records to confirm it’s not already in use.
2. Use a Name That Reflects Email Sending
Choose a subdomain that clearly indicates it’s used for sending emails. This helps:
Avoid confusion when managing DNS settings
Prevent accidental edits or deletions
Keep your setup organized
Simple and descriptive names like send, emails, or newsletter work well.
3. Avoid Commonly Reserved Subdomains
Some subdomains, like “mail”, are often already used for inbox or mail server configurations. Using them for sending emails can create conflicts or confusion, so it’s best to avoid them.
4. Keep It Consistent with Your Brand
Your subdomain should align with your brand and communication style. While it doesn’t need to be customer-facing, consistency helps maintain a clean and professional setup.
Key Takeaway
A branded sending subdomain is a small but important part of your email setup. Choosing a clear, unique, and purpose-driven subdomain helps maintain an organized infrastructure and supports better email deliverability over time.
Learn how authentication works with your domain setup: Understanding Email Authentication.