If your import matches a subscriber who is already globally unsubscribed or marked invalid, that status remains in place. Updating the subscriber's details or adding them to another list does not make them subscribed or valid again.

For example, when you import an updated first name for Alex into your Newsletter list:

• The name and list membership can be updated.
• Alex's existing global unsubscribe remains in place.

You can use an import to set an unsubscribe or invalid flag. Entering a false value, such as n, or leaving the cell blank does not remove a flag that is already set.

Other profile information can still change:

• Mapped values can update the subscriber's details.
• Blank mapped text or custom-field values can clear existing data.
• Omitted or ignored fields are left unchanged.

The same principle applies to an unsubscribe from one particular list: importing a false or blank Unsubscribe flag does not resubscribe that existing list membership. Use the separate status-reset process when a subscriber should be resubscribed and you have the appropriate permission to do so.

See import logic, uploading unsubscribed users, and resetting an unsubscription status.