A one-click unsubscribe header lets supported inbox providers show an unsubscribe option near the sender information in the email client. It gives subscribers a fast way to opt out without searching through the message body.

In Mailcamp, marketing emails can include unsubscribe headers when the message is sent to a real subscriber and an unsubscribe URL is available. You should still include a visible unsubscribe link in the email body.

What the header does

• It adds unsubscribe information to the technical headers of the email.

• Supported inbox providers can use it to show a native unsubscribe button or link.

• It helps subscribers leave your audience cleanly instead of marking your email as spam.

• It supports Google and Yahoo sender requirements for many commercial or promotional messages.

• It works together with the normal unsubscribe link inside the email body.

How Mailcamp handles it

• Mailcamp generates a unique unsubscribe URL for each subscriber.

• When the unsubscribe URL is available, Mailcamp adds a List-Unsubscribe header to the email.

• Mailcamp also adds List-Unsubscribe-Post: List-Unsubscribe=One-Click for one-click unsubscribe support.

• If a tracking domain is used, Mailcamp can build the unsubscribe URL through the selected tracking domain.

• When a subscriber unsubscribes, Mailcamp updates the subscriber status and records unsubscribe activity in reports.

What you need to do

• Add a visible unsubscribe link to every marketing campaign.

• Use the {UNSUBSCRIBE_URL} tag when editing email content or templates.

• Do not remove the unsubscribe link from the footer or hide it with tiny text or low contrast styling.

• Review the unsubscribe form and unsubscribe success page for the connected list.

• Send to subscribers who opted in, so unsubscribe and complaint rates stay healthy.

Where to review unsubscribe pages

• In Mailcamp, go to Lists.

• Open the audience/list used by your campaign.

• Open the unsubscribe-related pages for that list.

• Review the Unsubscribe form.

• Review the Unsubscribe success page.

• If needed, review the unsubscribe goodbye email or unsubscribe notification settings.

Why you still need an unsubscribe link in the email

• Some inbox providers may not display the native unsubscribe button for every message.

• Gmail and Yahoo decide whether to show the native unsubscribe option based on their own checks.

• A visible in-email unsubscribe link gives subscribers a clear backup option.

• Mailcamp may require the {UNSUBSCRIBE_URL} tag before allowing a marketing campaign to be saved or sent.

• A clear unsubscribe process helps reduce spam complaints and protect sender reputation.

Best practices

• Place the unsubscribe link in the footer where subscribers expect to find it.

• Use simple text such as Unsubscribe or Click here to unsubscribe.

• Make sure the unsubscribe page works before sending a campaign.

• Use a verified sending domain for your From email.

• Use a custom tracking domain when your plan supports it.

• Monitor unsubscribe and complaint rates after each campaign.

Troubleshooting

• Mailcamp asks for an unsubscribe link: add the {UNSUBSCRIBE_URL} tag to the email content.

• The native Gmail unsubscribe button does not appear: inbox providers control whether the button is shown, even when headers are present.

• The unsubscribe link opens the wrong page: review the unsubscribe pages for the connected list.

• Test emails behave differently: one-click unsubscribe headers are most meaningful when sending to real subscribers with generated unsubscribe URLs.

• Unsubscribe rate is high: review list quality, sending frequency, and whether subscribers expected the content.