Why Domain Reputation Makes or Breaks Your Outlook Deliverability

When it comes to Outlook, your domain’s reputation isn’t just important — it is everything.

Outlook looks beyond SPF and DKIM. It tracks how long your domain has been sending, how consistently, and whether your past emails caused complaints or bounces. New domains or domains with little sending history raise red flags.

If you’re using a freshly minted domain or one that sends erratically, Microsoft treats you like a potential spammer. Even if your emails are legitimate, they land in the junk folder.

This is why you can’t just spin up a new domain, plug it into a standard ESP, and expect flawless delivery to Outlook addresses.

Lemon Email helps by enforcing domain reputation best practices. It ensures your sending domain is aged, stable, and properly authenticated. We separate transactional from marketing traffic, so your domain’s reputation remains clean.

More importantly, we monitor feedback loops and complaints, adjusting sending behavior to maintain trust. It’s like building a solid credit score for your domain with Microsoft.

If your domain reputation is weak, no amount of tweaking headers or content will help. Outlook’s filters put more weight on history and consistency than any message copy.

Building and maintaining a good domain reputation is slow and requires precision. Lemon Email does this heavy lifting for you, so your transactional emails don’t just get sent, they get seen.