Omnivery is a European transactional SMTP relay platform serving developers, SaaS teams, and e-commerce merchants with API-based sending, high-volume throughput, and GDPR-compliant EU data residency. The unsubscribe mechanism uses the {{unsubscribe_url}} merge variable that developers must place manually in the email template body. RFC 8058 headers can be configured through the API metadata parameters when sending marketing-classified messages. Consent is tracked at the recipient level. This guide covers the variable, the EU data residency model, and how to verify the setup end to end.
Omnivery unsubscribe link
| Tag syntax | {{unsubscribe_url}} |
| Placement | Manual placement in email template body |
| Scope | Recipient-level opt-out with account-wide suppression |
| Config path | API > Send > List-Unsubscribe headers parameter |
| RFC 8058 one-click | Manual via API metadata parameters for marketing sends |
How to add the unsubscribe tag in Omnivery
Place the merge tag exactly as shown below in the email template. Omnivery replaces it at send time with a signed URL scoped to the recipient and campaign.
{{unsubscribe_url}}For custom HTML templates, wrap the tag in an anchor to render a proper hyperlink in the delivered email:
<a href="{{unsubscribe_url}}">Unsubscribe from this list</a>Manual placement in email template body
Manual via API metadata parameters for marketing sends 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.
Omnivery transactional SMTP relay requires developers to explicitly opt into RFC 8058 header injection per API call for marketing-classified sends. Pure transactional sends do not require the headers. GDPR-compliant EU data residency is a key differentiator versus US-based Postmark, SendGrid, and Mailgun for European SaaS teams with data localization requirements.
Testing your Omnivery unsubscribe link
- Send a test message to a controlled Gmail address you own via the Omnivery 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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See the pillar guide with the compliance landscape, the RFC 8058 deep dive, and the unsubscribe tag for every ESP: How to add an unsubscribe link: the complete 2026 guide →
How to add the Omnivery unsubscribe link (step by step)
Omnivery is developer-first with API-based template management. The unsubscribe variable inserts directly in the HTML body during template preparation.
- Prepare the email template with the placeholder
{{unsubscribe_url}}in the footer. - Include an anchor:
<a href="{{unsubscribe_url}}">Unsubscribe</a>. - In the API send call, populate the recipient-scoped unsubscribe URL in the merge variables object.
- For marketing-classified sends, include the
List-UnsubscribeandList-Unsubscribe-Postheaders in the API metadata parameters. - Configure webhook handlers to update the recipient s consent state on unsubscribe events.
- Send a test to a seed address and verify the rendered link routes to your recipient-scoped unsubscribe handler.
EU data residency and GDPR compliance
Omnivery GDPR-compliant EU data residency is a key differentiator versus US-based Postmark, SendGrid, and Mailgun for European SaaS teams with data localization requirements. All processing infrastructure operates within the EU, with data processing agreements (DPAs) available for enterprise contracts. Recipient consent state, engagement events, and message content remain within EU jurisdiction, matching GDPR data localization preferences for regulated industries (financial services, healthcare, public sector) subject to national supervisory authority review.
RFC 8058 one-click headers via API metadata
Omnivery transactional SMTP relay requires developers to explicitly opt into RFC 8058 header injection per API call for marketing-classified sends. Pure transactional sends do not require the headers. Missing the metadata parameter on marketing sends silently falls out of one-click compliance. Configure the send API wrapper to inject the headers by default for any campaign category classified as marketing. This is the standard developer-first pattern shared with SendGrid, Mailgun, Postmark, SparkPost, and emailDelivery.email.
High-volume throughput and rate limits
Omnivery high-volume throughput serves e-commerce peak seasons (Black Friday, Cyber Monday, Christmas) with dedicated IP pools available for senders exceeding 100k emails/day. Suppression list synchronization must keep pace with high-volume sending: on unsubscribe or hard bounce events, the recipient must be added to suppression before the next batch send to avoid double-sends. Use webhook-driven suppression sync rather than periodic polling for high-volume accounts.
Frequently Asked Questions
What is the Omnivery unsubscribe variable?
The merge variable is {{unsubscribe_url}}. Populate the recipient-scoped unsubscribe URL in the API send call merge variables object. Use it inside an anchor: <a href="{{unsubscribe_url}}">Unsubscribe</a>.
Is Omnivery data hosted in the EU?
Yes. All processing infrastructure operates within the EU with data processing agreements available for enterprise contracts. Recipient data remains within EU jurisdiction, matching GDPR data localization preferences for regulated industries.
Does Omnivery support one-click unsubscribe?
Yes via API metadata. Include the List-Unsubscribe and List-Unsubscribe-Post headers in the API metadata parameters on marketing-classified sends. SPF and DKIM alignment on the sender domain is prerequisite.
Can Omnivery handle Black Friday volume?
Yes. Dedicated IP pools available for senders exceeding 100k emails/day. Use webhook-driven suppression sync rather than periodic polling to keep suppression pace with high-volume batches during peak seasons.
How does Omnivery compare to SendGrid or Mailgun?
Both are transactional SMTP relays with API-based sending. Omnivery differentiates on EU data residency and GDPR compliance for European senders. Feature differences (webhook granularity, pricing, template management) inform vendor selection.
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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