> For the complete documentation index, see [llms.txt](https://docs.sendman.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sendman.com/other/faqs/security-and-privacy.md). # Security & Privacy ## How is my instance separated from other customers? Every customer gets a dedicated Sendman instance with its own configuration, its own Admin Portal and its own encryption key. Instances are isolated from each other on the network level. ## How are passwords stored? * **SMTP credentials:** passwords are encrypted with AES-256-GCM using a key that is unique to your instance. They cannot be displayed again, neither in the Admin Portal nor through the API. * **Backend password and client certificate:** stored encrypted and never returned by the Admin Portal or the API. * **Pre-shared keys and WireGuard private keys** of [network connections](/admin-portal/settings/network-connections.md) are stored as secrets and masked in the Admin Portal. ## Are passwords written to the logs? No. Neither the passwords your clients sign in with nor the credentials Sendman uses at your backend appear in the [logs](/admin-portal/insights/logs.md). ## Which connections are encrypted? * **Clients to Sendman:** TLS 1.2 or TLS 1.3, with STARTTLS on ports 587 and 25 or implicit TLS on port 465. On ports 587 and 465, clients can only sign in after TLS is established. * **Sendman to your backend:** STARTTLS whenever your backend offers it, optionally with a client certificate (mutual TLS). * **Network connections:** WireGuard or IPsec (IKEv2). * **Admin Portal and API:** HTTPS only. ## Who can access the Admin Portal? Only accounts you list as administrators or viewers under [Permissions](/admin-portal/settings/permissions.md). Sendman does not manage its own administrator accounts; administrators sign in with their existing identity provider. After an offboarding, you can [invalidate all issued sessions](/admin-portal/settings/permissions.md#session-security). ## How can I prevent Sendman from being misused as an open relay? Sendman only accepts connections from your [IP Allow List](/admin-portal/sendman/ip-allow-list.md) and only accepts messages that an [authorization policy](/admin-portal/sendman/authorization-policies.md) explicitly allows. In addition: * Keep allow-list ranges as narrow as possible. * Prefer authentication over anonymous sending, and limit anonymous policies to the addresses of the devices that need them. * Restrict **Allowed receivers** where possible, e.g. to your own domains. * Use a separate [SMTP credential](/admin-portal/sendman/smtp-credentials.md) per device or application, so you can revoke it individually. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.sendman.com/other/faqs/security-and-privacy.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.