SMTP

Host a copy with our keys and logs.

• SMTP_HOST — Hostname of the SMTP server, e.g. smtp.example.net.
• SMTP_PORT — Port. Defaults to 587 for starttls, 465 for implicit, 25 for none.
• SMTP_TLS — starttls (default), implicit or none. STARTTLS is required, never opportunistic.
• SMTP_USER — Username for SMTP authentication.
• SMTP_PASSWORD — Password or app-specific password for SMTP authentication.
• SMTP_FROM — The only sender this server will use, e.g. "Name <[email protected]>". There is no from parameter.
• SMTP_REPLY_TO — Reply-To header on every message, e.g. "Team <[email protected]>". Unset means no Reply-To header and replies go to SMTP_FROM. There is no reply_to parameter.
• SMTP_ALLOW_SEND — Set to "true" to register the sending tools. Defaults to false: the server cannot send until it is set.
• SMTP_ALLOWED_RECIPIENTS — Comma-separated addresses and @domains this server may write to. Required with SMTP_ALLOW_SEND=true; "*" allows any.
• SMTP_MAX_RECIPIENTS — Maximum distinct recipients across To, Cc and Bcc in one message. Default 10.
• SMTP_MAX_SENDS_PER_HOUR — Sliding hourly cap on messages sent. Default 20.
• SMTP_MAX_MESSAGE_BYTES — Maximum size of the composed message. Default 10485760.
• SMTP_MAX_ATTACHMENT_BYTES — Maximum size of a single attachment. Default 5242880.
• SMTP_ATTACHMENT_DIR — Directory attachments are read from. Unset means attachments are unavailable.
• SMTP_ATTACHMENT_TYPES — Comma-separated content types that may be attached. Defaults to a document and image allowlist.
• SMTP_SIGNATURE — Text appended below the standard signature delimiter of every message.
• SMTP_AUDIT_LOG — File the audit lines are appended to, in addition to stderr.
• SMTP_ALLOW_TOOLS — Comma-separated tool names, a prefix with one trailing *, or "essential" for the curated preset.
• SMTP_DENY_TOOLS — Comma-separated tool names or prefixes to remove, applied after SMTP_ALLOW_TOOLS.
• SMTP_INSECURE_TLS — Set to "true" to accept self-signed certificates. Prefer a proper internal CA.