Allowlist

What Is an Allowlist in Emailing?

An allowlist (formerly known as a whitelist) is a list of trusted email senders, domains, or IP addresses that are explicitly permitted to deliver messages to a recipient’s inbox.

When a sender is on an allowlist, their messages bypass certain spam filters or security checks, reducing the risk of legitimate mail being mistakenly marked as spam.

Allowlists are commonly used by organizations and mailbox providers to ensure consistent delivery from verified and reputable sources.

How Allowlists Work

Allowlists function by giving preferential treatment to approved senders at various points in the email delivery process.

An allowlist can exist at multiple levels:

• User-level allowlists, managed within personal email clients, which mark specific senders as “safe.”
• Domain or server-level allowlists, managed by IT or security teams, which authorize known domains, IPs, or mail gateways to bypass certain filters.
• Third-party service allowlists, where email platforms (like marketing tools) register trusted sending domains to improve deliverability.

In many cases, being on a recipient’s allowlist can significantly increase the likelihood of reaching the inbox.

Why Allowlists Are Important for Organizations Relying on Email

Allowlisting plays an important role in balancing email security and deliverability.

Without an allowlist, even legitimate senders with proper SPF, DKIM, and DMARC authentication might occasionally land in spam due to content filters or low engagement.

By maintaining a clean and verified allowlist, organizations can reduce unnecessary delivery issues and ensure that critical communications, such as invoices, password resets, or internal updates, always reach their intended recipients.

But allowlists must be managed carefully. Overly broad entries can let malicious senders bypass protection, especially if a compromised system shares an IP with an allowed domain.

Allowlists and DMARCeye

While DMARC itself doesn’t rely on allowlists, monitoring your authentication data through DMARCeye helps you identify which senders consistently pass SPF, DKIM, and DMARC checks, and therefore qualify for allowlisting.

DMARCeye provides visibility into your legitimate sending sources, helping you separate trusted partners from unauthorized ones. With this data, you can maintain a precise, security-conscious allowlist that supports both strong protection and high deliverability.

Sign up for a free trial of DMARCeye today to secure your email domain.

To learn more about DMARC and DMARC-related terms, explore the DMARCeye Glossary.