Acceptable Use Policy

1. Customer Responsibility

Mailrun provides email infrastructure and related operational services. Mailrun does not create, select, or send customer communications on a customer's behalf.

Customers are solely responsible for:

• The content and recipients of communications sent through Mailrun-provided infrastructure;
• Determining whether their communications are lawful and appropriate;
• Obtaining any consent, authorization, or other legal basis required for their communications;
• Maintaining accurate sender information and suppression records;
• Complying with applicable laws, regulations, industry requirements, and service-provider rules; and
• The actions of their employees, contractors, clients, and other authorized users.

2. Lawful and Responsible Use

Customers may use the Services for lawful business communications, including outbound business email, provided that their use complies with this AUP, the Terms of Service, and all applicable legal and regulatory requirements.

Customers must:

• Accurately identify the person or organization responsible for each communication;
• Use accurate sender names, addresses, domains, routing information, and subject lines;
• Include sender identification, contact information, and an unsubscribe mechanism when required;
• Honor unsubscribe, objection, and suppression requests promptly;
• Maintain reasonable list hygiene and remove addresses that are invalid, inactive, suppressed, or generating repeated complaints;
• Use only domains, mailboxes, credentials, and other resources they are authorized to use; and
• Take reasonable measures to prevent unauthorized access to their accounts and infrastructure.

3. Prohibited Conduct

Customers may not use, or permit others to use, the Services to engage in, facilitate, or promote conduct that:

• Violates applicable law, regulation, court order, or legally binding industry requirement;
• Is fraudulent, deceptive, misleading, defamatory, abusive, or otherwise unlawful;
• Involves phishing, impersonation, credential theft, malware, malicious code, or unauthorized access;
• Conceals or falsifies the identity of a sender or the origin of a communication;
• Uses forged headers, deceptive subject lines, misleading display names, or unauthorized domains;
• Continues sending to recipients after a valid opt-out, objection, or suppression request;
• Uses purchased, rented, scraped, harvested, or third-party contact data without a legally sufficient basis or authorization to contact the recipients;
• Infringes or misappropriates intellectual property, privacy, publicity, confidentiality, or other rights;
• Exploits or endangers minors or promotes unlawful goods, services, or activity;
• Interferes with or disrupts Mailrun's systems, networks, security controls, or service providers;
• Attempts to gain unauthorized access to accounts, systems, data, domains, or mailboxes;
• Attempts to evade sending limits, warm-up requirements, suppression controls, security measures, or other operational restrictions;
• Generates traffic or activity that materially threatens the reputation, availability, security, or deliverability of Mailrun infrastructure or associated service providers; or
• Exposes Mailrun, its service providers, or other customers to material legal, operational, security, or reputational risk.

The examples above are not exhaustive. Mailrun may determine that conduct violates this AUP when, based on the available facts, it presents a material risk to the Services, Mailrun, its service providers, other customers, or third parties.

4. Infrastructure and Deliverability Standards

Customers must operate within the technical and operational standards communicated by Mailrun. Mailrun may review sending and infrastructure signals including delivery failures, bounce activity, complaint activity, blocklist events, authentication failures, provider notices, unusual traffic patterns, and other information reasonably necessary to operate and protect the Services.

Customers must not:

• Circumvent technical limits or operational controls;
• Continue activity that is causing repeated provider rejections, complaints, or blocklisting;
• Rotate domains, mailboxes, accounts, or identities for the purpose of avoiding enforcement;
• Use Mailrun infrastructure to test stolen credentials, enumerate accounts, or validate unlawfully obtained contact data; or
• Resell, transfer, sublicense, or provide access to the Services except as expressly permitted by Mailrun.

Mailrun may establish or update reasonable technical and operational requirements when necessary to protect the Services or comply with service-provider requirements.

5. Investigations and Cooperation

Mailrun may investigate suspected violations based on complaints, automated signals, service-provider notifications, legal requests, or other credible information. Customers must provide reasonable and timely cooperation with an investigation, including information concerning:

• The identity of the sender;
• The source and intended use of recipient data;
• The basis for contacting recipients;
• Suppression and opt-out handling;
• The security of the customer's account; and
• Any corrective action taken or proposed.

Failure to cooperate with a reasonable investigation may itself constitute a violation of this AUP. Mailrun may disclose information when required by law or when reasonably necessary to protect the Services, Mailrun, its customers, service providers, or third parties, subject to the Terms of Service and Privacy Policy.

6. Enforcement

Mailrun may take action when it reasonably determines that a customer or authorized user has violated this AUP or that continued activity presents a material risk. Depending on the nature, severity, and urgency of the issue, Mailrun may:

• Request corrective action;
• Restrict or throttle activity;
• Disable affected domains, mailboxes, or credentials;
• Isolate infrastructure;
• Suspend some or all Services;
• Terminate the customer's account; or
• Take other reasonable steps necessary to protect the Services and affected parties.

Mailrun may act without prior notice when immediate action is reasonably necessary to address suspected fraud, unlawful activity, security threats, provider intervention, active blocklisting, or material risk to shared infrastructure. When appropriate, Mailrun will notify the customer and provide an opportunity to respond or remediate.

Suspension or termination resulting from a violation of this AUP is subject to the Terms of Service, including any provisions governing refunds and termination for cause.

7. Reporting Abuse

Suspected misuse of Mailrun infrastructure may be reported through our contact form. Reports should include sufficient information for Mailrun to identify and investigate the activity, such as the sending domain, sender address, message headers, dates, and a description of the suspected violation.

8. Changes to This Policy

Mailrun may update this AUP to reflect changes in the Services, applicable requirements, security risks, or industry practices. Material changes will be communicated as provided in the Terms of Service. Continued use of the Services after an updated AUP becomes effective constitutes acceptance of the revised policy.