Subdomain vs root domain for sending

Many email programmes are healthier when promotional or bulk mail is isolated on a subdomain. That does not automatically solve deliverability, but it often makes management clearer.

Why send on a subdomain

A subdomain can isolate reputation, simplify provider setup and avoid mixing high-volume promotional sending too closely with core business correspondence.

When root domain sending still makes sense

Low-volume business mail, executive correspondence and transactional use cases often remain tied to the primary domain for branding and trust reasons.

A practical structure

  • example.com for core business mail
  • news.example.com or mg.example.com for bulk or platform sending
  • Separate DKIM selectors and DMARC monitoring as needed

How to decide

Think in terms of reputation isolation, operational clarity and how many different platforms send on your behalf.

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