SMTP settings

Every setting below is read once at startup and requires a restart to change. Built-in defaults are overridden by nonempty environment values. Unknown FANOUT_ names fail startup; platform-injected service names are tolerated. Custom names use FANOUT_ plus a clear name, adding the area only when it clarifies. Vendor credentials and endpoints keep the vendor’s documented names.

Environment variable	Type	Default
FANOUT_SMTP_FROM	string	—
FANOUT_SMTP_HOST	string	—
FANOUT_SMTP_PASSWORD or FANOUT_SMTP_PASSWORD_FILE	string · secret	—
FANOUT_SMTP_PORT	integer	587
FANOUT_SMTP_USERNAME	string	—

Notes

FANOUT_SMTP_FROM

Sets the email sender address; required with SMTP.

FANOUT_SMTP_HOST

Selects the mail server. Host, username, password, and from must all be set to enable SMTP.

FANOUT_SMTP_PASSWORD

Authenticates to the mail server; required with SMTP.

FANOUT_SMTP_PORT

Sets the mail server’s positive TCP port.

FANOUT_SMTP_USERNAME

Authenticates to the mail server; required with SMTP.

Secrets

Settings marked secret are redacted from Fanout’s startup configuration log. Supply either the value or its _FILE path, never both. File contents lose exactly one trailing newline (LF or CRLF); empty secrets fail startup.