Sendfully
Deliverability

Subdomains vs root domains

We recommend using a subdomain for sending emails (e.g., mail.yourdomain.com) rather than your root domain (e.g., yourdomain.com) - a best practice shared by most email services. Here's why this is a good idea.

Protects your main domain's reputation

Every domain builds up a sending reputation over time based on how recipients interact with your emails. If you send from a subdomain and something goes wrong - maybe a campaign gets flagged as spam - only that subdomain's reputation is affected. Your root domain stays safe.

This protection is especially valuable because your root domain is likely used for other things like your website, corporate email, and other services.

Keeps your brand organized and consistent

Subdomains let you organize your email sending by purpose while keeping everything under your main domain. For example:

  • newsletter.yourdomain.com for your weekly updates
  • alerts.yourdomain.com for important notifications

This helps inbox providers understand the purpose of your emails, which can even help prevent them from being marked as spam. And since everything stays under your main domain, your brand remains recognizable to your audience.


Ready to set up your sending domain? Head over to the domain setup guide to get started.

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