A Postfix SMTP access policy delegation handler written in Rust. It handles protocol parsing and response sending to talk to Postfix.
examples/request_dump.rs contains a small example that spawns a policy server listening on /tmp/policy_example, that dumps all incoming policy requests to stdout. Postfix can be configured to use it by using check_policy_service { unix:/tmp/policy_example, default_action=DUNNO }.
See recipientfilter for a complete example how to use it.