Compliance
What is List-Unsubscribe Header?
An email header (RFC 2369) that gives mailbox providers a machine-readable way to let recipients unsubscribe directly from the inbox.
List-Unsubscribe is a message header that advertises one or more unsubscribe methods, historically a mailto: address and/or an HTTPS URL. Mailbox providers such as Gmail and Yahoo parse it to render a native Unsubscribe control next to the sender name. It is paired with the List-Unsubscribe-Post header to enable one-click unsubscribe (RFC 8058), and as of 2024 it is effectively mandatory for bulk senders.
Why it matters for cold email
Cold email lives in a gray zone, but adding List-Unsubscribe gives recipients a low-friction exit that is far healthier for your reputation than a spam complaint, which filters weigh much more heavily. Gmail and Yahoo bulk-sender rules require it for high-volume senders, and omitting it can get mail throttled or blocked.
Related terms
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