Acceptable Use Policy

Last updated: 5 October 2026

This policy is part of our Terms of Service. You must not use PlainMailOS, or let anyone else use it, to:

• break any law or anyone's rights, including privacy and data-protection law;
• connect or read a mailbox you are not authorized to access, or connect employees' mailboxes without the authority and the notices your law requires;
• get around the permissions of an organization or mailbox, or another customer's access controls;
• send spam, phishing, malware or other harmful or deceptive messages;
• harass, threaten or defame anyone;
• probe, scan or test the security of PlainMailOS without our written permission (responsible reports of vulnerabilities you came across are welcome; see our security page);
• overload the Service, get around rate limits or plan limits, or interfere with other customers' use;
• copy, resell or reverse-engineer the Service, or use it to build a competing product, without our written consent.

If we believe this policy has been broken, we may remove access to the content or suspend the account involved, and we will tell you unless the law or an ongoing investigation prevents it. To report abuse, email grievance@plainmailos.com.