Whitelist

A whitelist (allowlist) is a list of email addresses, domains, or IPs a recipient or mail administrator has marked as trusted so their messages are less likely to be filtered.

Sep 10, 2026

A whitelist, now more often called an allowlist, is a list of email addresses, domains, or IP addresses that a recipient or mail administrator has marked as trusted. Mail from those senders is meant to skip some or all of the filtering that would otherwise apply.

Where whitelists live

Whitelists exist at several levels. An individual can add a sender to a safe-sender list or address book in their mail client. A company's mail administrator can allowlist a domain or IP at the gateway so it reaches every employee. Mobile mail apps have their own settings. What a given list actually does depends on the client or server that manages it, so a sender should not assume that being whitelisted in one place means anything in another.

What it means for senders

You cannot whitelist yourself. The most a sender can do is ask. Some senders include a short line in a welcome email asking new subscribers to add the sending address to their contacts, and some publish a short how-to for common mail clients. A whitelist helps only for the recipients who set it up and does nothing for everyone else, so it does not replace authentication, list hygiene, or sender reputation. Treat it as a small supplement to the practices covered under email deliverability.

Guides