Global Headers let you add custom email headers that are automatically included in every email sent through Mumara Campaigns. You manage them under Settings → Global Headers. Headers are metadata fields that travel with each message — they're visible in the email source ("Show Original" in most email clients) and can be read by receiving mail servers or downstream systems.
Common uses include internal tracking (e.g., X-Campaign-Name to identify the source campaign), passing data to external systems (X-CRM-Contact-ID), compliance and abuse-reporting headers (X-Report-Abuse), and deliverability headers such as List-Unsubscribe-Post for one-click unsubscribe. To add one, click Add New and enter a Key (the header name) and a Value. Values can be static text, personalization tags like {{campaign_id}} or {{contact_id}}, or a mix of both. You can edit or delete headers individually, or delete several at once with bulk actions.
Worth knowing: header keys may only contain letters, numbers, and hyphens — no spaces or special characters — and custom headers conventionally start with X-. Global headers apply to ALL emails from the system; for campaign-specific headers, configure them on the individual broadcast instead (a broadcast header with the same key typically overrides the global one). Keep headers minimal, and verify they survive delivery by sending a test email and viewing its source — some ESPs strip or modify custom headers.
