Mailster is a self-hosted WordPress email marketing plugin serving WordPress sites wanting fully-owned newsletter infrastructure with drag-and-drop editor, subscriber management, and automation flows. The unsubscribe mechanism uses the {unsubscribelink} placeholder auto-injected into every campaign footer, and Mailster supports RFC 8058 header injection when configured in the sending engine settings. Suppression is tracked at the list level within the WordPress database. This guide covers the placeholder, the WordPress self-hosted model, and how to verify the setup end to end.
Mailster unsubscribe link
| Tag syntax | {unsubscribelink} |
| Placement | Auto-embedded in every campaign footer |
| Scope | Per-list opt-out within WordPress database |
| Config path | Mailster > Settings > Delivery > List-Unsubscribe |
| RFC 8058 one-click | Manual toggle in Mailster delivery settings |
How to add the unsubscribe tag in Mailster
Place the merge tag exactly as shown below in the email template. Mailster replaces it at send time with a signed URL scoped to the recipient and campaign.
{unsubscribelink}For custom HTML templates, wrap the tag in an anchor to render a proper hyperlink in the delivered email:
<a href="{unsubscribelink}">Unsubscribe from this list</a>Auto-embedded in every campaign footer
Manual toggle in Mailster delivery settings The recipient's mailbox provider (Gmail, Yahoo) uses the List-Unsubscribe-Post header to expose the native one-click button on the message. Requires domain authentication with DKIM and DMARC.
Mailster self-hosted deployment means the WordPress site owner must enable RFC 8058 header injection in the Mailster delivery settings and verify SPF, DKIM, and DMARC alignment on the WordPress sending domain. Delivery method (WordPress default wp_mail, external SMTP via WP Mail SMTP, Amazon SES, SendGrid) affects header injection reliability. Missing the toggle silently falls out of one-click compliance.
Testing your Mailster unsubscribe link
- Send a test message to a controlled Gmail address you own via the Mailster campaign preview action
- Click the footer unsubscribe link and confirm the opt-out on the landing page
- Check the subscriber or contact record: the status should be Unsubscribed within seconds
- Verify the RFC 8058 headers in Gmail: open the message, click three dots, then Show original. Look for
List-UnsubscribeandList-Unsubscribe-Post: List-Unsubscribe=One-Click
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How to add the Mailster unsubscribe link (step by step)
Mailster default templates include the unsubscribe placeholder in the footer, but custom HTML templates require the placeholder inserted manually.
- Open your campaign or template in the WordPress admin > Mailster > Templates.
- Add or edit a text block in the footer where the unsubscribe link should appear.
- Insert the placeholder
{unsubscribelink}. Mailster replaces it at send time with a signed URL scoped to the subscriber. - Wrap it in an anchor:
<a href="{unsubscribelink}">Unsubscribe</a>. - Enable RFC 8058 header injection under Mailster > Settings > Delivery > List-Unsubscribe.
- Send a test to a seed address and verify the rendered link routes to the Mailster-hosted subscriber preference page.
WordPress self-hosted delivery and SMTP integration
Mailster self-hosted deployment means the WordPress site owner must enable RFC 8058 header injection in the Mailster delivery settings and verify SPF, DKIM, and DMARC alignment on the WordPress sending domain. Delivery method (WordPress default wp_mail, external SMTP via WP Mail SMTP, Amazon SES, SendGrid) affects header injection reliability. Missing the toggle silently falls out of one-click compliance. High-volume WordPress newsletter sending typically routes through Amazon SES or a dedicated SMTP relay for deliverability, not the default wp_mail.
RFC 8058 one-click headers via Mailster settings
Mailster exposes RFC 8058 header injection as a delivery setting toggle. Once enabled, the List-Unsubscribe and List-Unsubscribe-Post headers inject on every marketing send from domains authenticated via the connected SMTP relay. Verify the delivery method supports header injection: some legacy SMTP setups strip custom headers. Test with a Gmail seed address to confirm the unsubscribe link appears at the top of the Gmail message header per RFC 8058 behavior.
Subscriber management and WordPress database
Mailster subscribers are stored in the WordPress database with GDPR-friendly export and delete workflows via WordPress core user data tools. Opt-out state is tracked per-list within the WordPress database. Automation flows (welcome series, RSS-to-email, drip campaigns) respect the opt-out flag at every send step. WordPress user role integration lets Mailster subscribers optionally correspond to WordPress users for gated content and member-only campaigns.
Frequently Asked Questions
What is the Mailster unsubscribe placeholder?
The placeholder is {unsubscribelink}. Mailster replaces it at send time with a signed URL scoped to the subscriber. Use it inside an anchor: <a href="{unsubscribelink}">Unsubscribe</a>.
Does Mailster support one-click unsubscribe by default?
Only when the delivery setting toggle is enabled. Missing the toggle silently falls out of one-click compliance. Verify the connected SMTP relay supports custom header injection to complete the chain.
Should I use default wp_mail or an external SMTP for Mailster?
External SMTP relay (Amazon SES, SendGrid, Mailgun, SMTPing) for any real newsletter sending. Default wp_mail relies on the WordPress server s outbound mail configuration which typically lacks SPF/DKIM alignment and hits Gmail bulk sender limits quickly.
Is Mailster GDPR-compliant?
Yes with proper configuration. Subscribers are stored in the WordPress database with GDPR-friendly export and delete workflows via WordPress core user data tools. Configure double opt-in for EU audiences to complete GDPR consent requirements.
How does Mailster compare to MailPoet for WordPress?
Both are WordPress email marketing plugins with similar core features. Mailster is a premium one-time-purchase model, MailPoet is freemium with per-subscriber pricing on higher tiers. Feature depth (automation, segmentation, template library) differs. Both require external SMTP for real newsletter sending.
About the Author
Alaa · LinkedIn
Email infrastructure specialist with 8+ years of hands-on experience in SMTP, deliverability, and email verification. I’ve configured and troubleshot mail systems across Postfix, Exchange, and cloud relays, managed IP reputation and warmup campaigns, and built verification pipelines processing millions of addresses. My work spans DNS authentication (SPF, DKIM, DMARC, BIMI), bounce handling, blocklist monitoring, and compliance frameworks including CAN-SPAM and GDPR. I write every article on SMTPedia to give email professionals, developers, and marketers the accurate, RFC-grounded reference they need.
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