Deliverability & Authentication

How to Improve Email Deliverability

Email deliverability determines whether your messages reach the inbox or get flagged as spam. OutSends provides authentication tools, reputation monitoring, and best practices to maximize inbox placement.

Time: 20 min
Level: Intermediate
deliverability inbox placement sender reputation email authentication

What you'll need

Before you start, make sure you have the following ready.

  • An OutSends account
  • Access to your domain DNS settings
  • Recent campaign delivery data

Step-by-step guide

Follow these steps to complete the setup.

Authenticate your domain

Set up SPF, DKIM, and DMARC DNS records. These tell ISPs that your emails are legitimate.

Monitor sender reputation

Use OutSends reputation dashboard to track your sender score, complaint rate, and blocklist status.

Maintain list hygiene

Remove inactive subscribers, validate new addresses, and handle bounces promptly. A clean list is the #1 factor.

Optimize sending frequency

Don't over-send. 2-4 campaigns per month per list is ideal for most industries. Respect your subscribers' inbox.

Test before big sends

Use OutSends spam testing to check how your email renders across providers. Fix issues before hitting "send."

Tips for best results

Pro tips to get the most out of this setup.

  • Never buy email lists — purchased lists destroy deliverability
  • Include a one-click unsubscribe link in every email (CAN-SPAM requirement)
  • Consistent volume beats burst sending — ISPs prefer predictable patterns

Frequently asked questions

What is the most important deliverability factor?

List quality. ISPs prioritize engagement signals. If people open and reply, you go to the inbox.

How do I check if I'm on a blocklist?

OutSends includes automatic blocklist monitoring. You can also check manually using MXToolbox.

Can I recover from a spam complaint spike?

Yes, but it takes time. Stop sending, clean your list, authenticate your domain, and slowly rebuild volume.

Related guides

Explore more how-to guides for OutSends.

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