Acceptable Use Policy

You may only send emails to recipients where you have a lawful basis to do so. Acceptable bases include:

• Explicit prior consent from the recipient to receive commercial emails from you.
• A genuine legitimate interest basis, where the email is relevant, proportionate, and the recipient would reasonably expect contact — and you have completed a balancing test.
• An existing business relationship or contractual necessity, where applicable law permits.

You are responsible for the legality and quality of your contact lists. The following list practices are prohibited:

• Sending to purchased, rented, or scraped lists where recipients have not given consent or there is no legitimate interest basis.
• Harvesting email addresses from public sources without a clear legal basis.
• Sending to role-based or catch-all addresses without clear indication that an individual has consented.
• Using third-party lists without verifying that the list source obtained proper consent.

You must honor unsubscribe and opt-out requests promptly. zend.sh auto-appends CAN-SPAM-compliant unsubscribe links to outbound emails and provides a GDPR suppression API. You must not circumvent, modify, or suppress these mechanisms.

When a recipient unsubscribes or opts out, you must not re-add them to sending lists or re-contact them for marketing purposes without new explicit consent.

Suppression lists must be maintained and applied across all lists sent via zend.sh.

You must comply with all applicable laws and regulations governing commercial email, including but not limited to:

• CAN-SPAM Act (USA): accurate From/Reply-To headers, a physical mailing address, clear identification as an advertisement where required, and a working unsubscribe mechanism honored within 10 business days.
• GDPR (EU/EEA): a valid lawful basis for processing, data minimization, and respecting data subject rights.
• CASL (Canada): express or implied consent before sending commercial electronic messages to Canadian recipients.
• Any other jurisdiction-specific requirements applicable to your recipients.

The following content and uses are prohibited on the Service:

• Illegal goods or services, including counterfeit products, narcotics, unauthorized pharmaceuticals, and weapons.
• Malware, phishing, or any content designed to deceive recipients into disclosing credentials or installing software.
• Fraud, scams, pyramid schemes, or materially false or misleading commercial claims.
• Harassment, threats, hate speech, or discriminatory content.
• Adult content sent without verified recipient age and consent.
• Anything that violates the terms of the connected sending providers (Google Workspace, Microsoft 365, Azure Communication Services, or other SMTP/IMAP providers you link).
• Spamming: sending bulk, unsolicited email at high velocity without prior recipient consent or a valid legitimate interest basis.

The zend.sh peer-to-peer warmup network depends on shared deliverability. You must not attempt to manipulate, abuse, or reverse-engineer the warmup network, inflate engagement signals artificially, or use warmup-enrolled accounts for mass commercial sending outside the warmup context.

Accounts found to be degrading the warmup network's reputation or deliverability for other users will be suspended immediately.

zend.sh monitors aggregate signals (bounce rates, spam complaint rates, unsubscribe rates) and may automatically pause or suspend sending if thresholds are exceeded. Accounts that repeatedly violate this AUP may be permanently terminated.

We reserve the right to investigate suspected violations and to cooperate with law enforcement where required. Reports of abuse can be sent to legal@zend.sh.

Suspension does not entitle you to a refund of prepaid fees, except where required by applicable law.