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Terms of Service

Last updated: March 27, 2026

1. Acceptance of Terms

By accessing or using PostStack ("Service"), operated by MICCI (CVR: 45587452, Fyrretoften 31, 7100 Vejle, Denmark), you agree to be bound by these Terms of Service ("Terms"). If you do not agree, do not use the Service. These Terms constitute a legally binding agreement between you and MICCI.

2. Description of Service

PostStack provides an email API platform for sending transactional and marketing emails. The Service includes domain verification (SPF, DKIM, DMARC), contact management with custom properties, email templates, broadcast campaigns, workflow automation, open and click tracking, webhook delivery, inbound email processing, dedicated IP provisioning, and usage-based billing.

3. Account Registration

You must provide accurate and complete information when creating an account. You are responsible for:

  • Maintaining the confidentiality of your account credentials, API keys, and webhook signing secrets
  • All activity that occurs under your account or API keys
  • Notifying us immediately of any unauthorized use of your account

You may authenticate via email and password or through a supported third-party provider (e.g., GitHub). You must not share API keys, create accounts on behalf of others without their consent, or attempt to access another user's account.

4. Acceptable Use Policy

You agree not to use the Service to:

  • Send unsolicited bulk email (spam) or messages to recipients who have not given consent
  • Send phishing emails or emails that impersonate another person or entity
  • Distribute malware, viruses, or any harmful or illegal content
  • Violate any applicable laws or regulations, including but not limited to CAN-SPAM, GDPR, PECR, ePrivacy Directive, and CASL
  • Harvest or collect email addresses without the owners' consent
  • Send emails with deceptive subject lines or misleading sender information
  • Attempt to circumvent rate limits, usage quotas, or security measures
  • Interfere with or disrupt the Service infrastructure or other users' access
  • Use the Service to send emails on behalf of a third party without proper authorization
  • Resell, redistribute, or sublicense access to the Service without our written consent
  • Reverse-engineer, decompile, or attempt to extract the source code of the Service (except as permitted by applicable law)
  • Use the Service to store or process special-category personal data (as defined by GDPR Article 9) without appropriate safeguards

Violation of this policy may result in immediate suspension or termination of your account without prior notice. We reserve the right to review outgoing emails for compliance and to reject or suspend sending that violates these Terms.

5. Email Content and Sender Responsibility

You are solely responsible for the content of all emails sent through the Service, including emails triggered by workflow automations. PostStack acts as a technical service provider and does not review, approve, or endorse the content of your messages. You must:

  • Have a lawful basis to send emails to each recipient (consent, contract, or legitimate interest as applicable under relevant law)
  • Include a valid physical mailing address or registered business address in marketing emails as required by CAN-SPAM and equivalent regulations
  • Provide a functional unsubscribe mechanism in all marketing and broadcast emails
  • Honor unsubscribe requests promptly (within 10 business days)
  • Accurately identify yourself as the sender and not use misleading subject lines or headers
  • Ensure email attachments do not contain malware or illegal content

6. Contact Data and Custom Properties

You may store contact information and custom properties about your recipients using the Service. You are the data controller for all contact data you store and are responsible for:

  • Ensuring you have a lawful basis to collect and store contact data
  • Not storing special-category data (health, racial/ethnic origin, political opinions, etc.) in custom contact properties without appropriate legal safeguards
  • Responding to data subject access, rectification, and deletion requests from your contacts
  • Keeping contact data accurate and up-to-date

7. Inbound Email Processing

If you enable inbound email processing for a domain, PostStack will receive, parse, and store emails sent to addresses on that domain. You are responsible for:

  • Informing senders (where practical) that emails are processed by a third-party service
  • Handling inbound email data in accordance with applicable data protection laws
  • Managing the retention and deletion of inbound email data through your account

8. API Usage and Security

Access to the PostStack API is subject to rate limits and usage quotas based on your plan. You must:

  • Keep API keys confidential and never expose them in client-side code, public repositories, or insecure environments
  • Rotate API keys if you suspect they have been compromised
  • Use the minimum required permission scope for each API key (e.g., sending-only keys where full access is not needed)
  • Not share API keys across unrelated applications or organizations

We reserve the right to throttle or suspend API access that exceeds rate limits, generates excessive errors, or is used in a manner that degrades the Service for other users.

9. Webhook Data and External Integrations

When you configure webhook endpoints, PostStack delivers email event data (including recipient addresses, event metadata, and tracking data) to your specified URLs. You are responsible for:

  • Securing your webhook endpoints (HTTPS, HMAC signature verification)
  • Handling webhook data in accordance with applicable data protection laws
  • Ensuring your endpoints respond promptly (failed deliveries are retried with exponential backoff, up to 3 attempts)

10. Billing and Payment

Paid plans are billed monthly in advance. Usage beyond your plan's included limits incurs overage charges as described on our pricing page. All fees are in the currency specified at time of subscription.

  • Payment is processed by Stripe. By subscribing, you also agree to Stripe's Terms of Service.
  • You may cancel your subscription at any time. Cancellation takes effect at the end of the current billing period. No pro-rata refunds are provided.
  • Refunds are not provided for partial months of service, unused email volume, or unused dedicated IP allocations.
  • We may change pricing with 30 days' notice via email. Continued use after the notice period constitutes acceptance of the new pricing.
  • Overdue accounts may be suspended after 14 days. We will notify you via email before suspension.
  • Free plan accounts that remain inactive for 12 consecutive months may be deleted after notice.

10.1 VAT and Taxes

Prices on our website and in checkout are exclusive of VAT (moms). The applicable VAT is added at checkout based on your billing address and, for business customers, your EU VAT identification number:

  • Denmark: Danish VAT at 25% is added to all sales.
  • Other EU countries (consumers): VAT of the destination country is added under the Union One-Stop Shop (OSS) scheme, in accordance with Article 58 of Directive 2006/112/EC.
  • Other EU countries (businesses): Where a valid EU VAT identification number is provided at checkout, the supply is zero-rated and the reverse-charge mechanism applies under Article 196 of Directive 2006/112/EC. Customer must account for VAT in its country of establishment.
  • Outside the EU: No EU VAT is charged. Customer is responsible for any import taxes, duties, or local consumption taxes that may apply in its jurisdiction.

Invoices issued by MICCI include MICCI's Danish CVR number (45587452), the VAT rate and amount applied, and — where relevant — the customer's VAT identification number and a reference to the reverse-charge mechanism. VAT calculation and invoicing are handled by Stripe Tax on our behalf.

11. Service Availability

We strive to maintain high availability but do not guarantee uninterrupted or error-free operation. The Service is provided on an "as is" and "as available" basis without any warranty, express or implied, including warranties of merchantability, fitness for a particular purpose, or non-infringement.

We may perform scheduled maintenance with reasonable advance notice when possible. We reserve the right to modify, suspend, or discontinue any part of the Service at any time. We will make reasonable efforts to provide at least 30 days' notice of material changes or discontinuation.

12. Intellectual Property

The Service, its design, features, documentation, and all related intellectual property are owned by PostStack. You retain all rights to your content (email content, templates, contact data, custom properties) that you submit through the Service.

By using the Service, you grant PostStack a limited, non-exclusive, royalty-free license to process your content solely for the purpose of providing the Service (e.g., delivering emails, rendering templates, generating analytics, running workflow automations). This license terminates when you delete the content or close your account.

13. Account Suspension and Termination

We may suspend or terminate your account if you:

  • Violate these Terms or the Acceptable Use Policy
  • Cause excessive bounces, spam complaints, or blacklisting that affects our shared sending infrastructure or other users' deliverability
  • Fail to pay outstanding invoices after notice
  • Use the Service in a way that poses a security risk to others
  • Are required by law or regulatory action to be removed from the Service

Where possible, we will provide notice and an opportunity to remedy the violation before suspension. In cases of severe abuse (spam, phishing, malware distribution), immediate suspension may occur without notice.

You may terminate your account at any time through the dashboard settings. Upon termination (whether by you or by us):

  • Your right to use the Service ceases immediately
  • We will retain your data for 30 days, during which you may request an export
  • After 30 days, all data will be permanently deleted (except billing records retained for legal compliance)
  • Any outstanding fees incurred before termination remain due and payable

14. Limitation of Liability

To the maximum extent permitted by applicable law, PostStack shall not be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of profits, data, reputation, goodwill, or business opportunities, even if we have been advised of the possibility of such damages.

Without limiting the foregoing, PostStack shall not be liable for:

  • Emails that fail to deliver due to recipient server policies, spam filters, or network issues
  • Damage to your sender reputation arising from your email practices
  • Data loss resulting from your failure to maintain backups
  • Actions taken by third-party services (Stripe, DNS providers, email providers)

Our total aggregate liability for any claims arising from or related to the Service is limited to the amount you paid to PostStack in the 12 months preceding the claim. Nothing in these Terms limits liability for fraud, gross negligence, death or personal injury caused by negligence, or any liability that cannot be excluded under applicable Danish or EU law.

15. Indemnification

You agree to indemnify, defend, and hold PostStack and its officers, employees, and agents harmless from any claims, damages, losses, or expenses (including reasonable legal fees) arising from:

  • Your use of the Service
  • The content of emails you send or receive through the Service
  • Contact data and custom properties you store through the Service
  • Your violation of these Terms or any applicable law
  • Your violation of any third party's rights, including intellectual property rights and privacy rights
  • Claims from your email recipients arising from your email practices

16. Data Protection

We process personal data in accordance with our Privacy Policy. When you use PostStack to send emails containing personal data of your end users, store contact data, or process inbound emails, you act as the data controller and PostStack acts as the data processor. You are responsible for ensuring you have a lawful basis to process your recipients' data and that your use of the Service complies with GDPR and other applicable data protection laws.

A Data Processing Agreement (DPA) is available upon request at privacy@poststack.dev.

17. Anti-Spam Compliance

You must comply with all applicable anti-spam laws, including the EU ePrivacy Directive, CAN-SPAM Act (United States), CASL (Canada), and any local regulations. You must only send emails to recipients who have given consent or with whom you have a legitimate relationship as defined by applicable law.

We monitor deliverability metrics (bounce rates, spam complaint rates) across the platform. Accounts generating bounce rates above 5% or complaint rates above 0.1% may be warned, throttled, or suspended to protect shared sending infrastructure and other users' deliverability.

18. Force Majeure

Neither party shall be liable for any failure or delay in performing its obligations under these Terms due to circumstances beyond its reasonable control, including but not limited to natural disasters, wars, terrorism, pandemics, government actions, power failures, internet or telecommunications failures, or cyberattacks. The affected party must notify the other party promptly and make reasonable efforts to mitigate the impact.

19. Governing Law and Disputes

These Terms are governed by and construed in accordance with the laws of Denmark, without regard to conflict of law principles. Any disputes arising from or relating to these Terms or the Service shall be subject to the exclusive jurisdiction of the courts of Copenhagen, Denmark.

Before initiating legal proceedings, both parties agree to attempt in good faith to resolve any dispute through informal negotiation for at least 30 days. If you are a consumer within the EU, you retain any mandatory consumer-protection rights under the laws of your country of residence.

20. Changes to Terms

We may update these Terms from time to time. Material changes will be communicated via email or a notice in the dashboard at least 30 days before they take effect. Continued use of the Service after the effective date constitutes acceptance of the updated Terms. If you disagree with the changes, you may terminate your account before the effective date.

21. General Provisions

  • Severability: If any provision of these Terms is found to be unenforceable or invalid, the remaining provisions shall remain in full force and effect.
  • Entire agreement: These Terms, together with the Privacy Policy and any applicable DPA, constitute the entire agreement between you and PostStack regarding the Service and supersede all prior agreements and understandings.
  • Waiver: Our failure to enforce any right or provision of these Terms shall not constitute a waiver of that right or provision.
  • Assignment: You may not assign or transfer your rights under these Terms without our prior written consent. We may assign our rights and obligations in connection with a merger, acquisition, or sale of assets, with notice to you.
  • No third-party beneficiaries: These Terms do not create any third-party beneficiary rights.

22. Contact

For questions about these Terms, contact us at:

PostStack v/ MICCI
Fyrretoften 31, 7100 Vejle, Denmark
CVR: 45587452
Email: support@poststack.dev
Phone: +45 42 22 30 83

See also: Privacy Policy