Simple SMTP Relay

Application written in Rust that listens for clients, reads e-mails and then delivers them using Azure Communication Services.

The server is inspired by the work done by Piotr Sarna.

Usage

$ ./simple_smtp_relay [<bind_address>:<port>] [<domain>]

By default, it binds to 127.0.0.1:25 with domain smtp.domain.com

Example:

$ ./simple_stmp_relay 127.0.0.1:2525 mydomain.com

The server uses standard Rust log library and uses RUST_LOG environment variable to control logging level (trace, debug, info, warn, error).

$ RUST_LOG=debug ./simple_smtp_relay

For e-mail delivery through ACS, two environment variables need to be set: ACS_ENDPOINT and ACS_ACCESS_KEY

$ RUST_LOG=debug ACS_ENDPOINT=https://<my_acs_account>.unitedstates.communication.azure.com ACS_ACCESS_KEY=<my_access_key> ./simple_smtp_relay