Emailrelay is a simple SMTP proxy and store-and-forward message transfer agent (MTA).\\ \\ When running as a proxy all e-mail messages can be passed through\\ a user-defined program, such as a spam filter, which can drop,\\ re-address or edit messages as they pass through. When running\\ as a store-and-forward MTA incoming messages are stored in a\\ local spool directory, and then forwarded to the next SMTP\\ server on request.\\ \\