Allowlist

An allowlist, formerly known as a whitelist, is a list of approved senders or recipients that are permitted to send emails to a particular inbox. It is used to ensure that emails from known and trusted sources are allowed to pass through a filter.

Allowlisting works by approving a list of email addresses, IP addresses or domains and automatically blocking all others. Allowlists work in contrast to blocklists or denylists which actively block emails from specific senders.