MeTA1 is a message transfer agent that has been designed with these main topics in minds:
* Security
* Reliability
* Efficiency
* Configurability
* Extendibility
MeTA1 consists of five main modules of which only one runs as root:
* mcp: the main control program is similar to inetd(8): it starts all other MeTA1 modules and watches over their
execution. mcp runs as root in order to bind to port 25 and to change the uid of the processes it starts.
* smtps: the SMTP server receives e-mails.
* smtpc: the SMTP client sends e-mails.
* smar: the address resolver provides lookups in various maps including DNS for mail routing.
* qmgr: the queue manager controls the flow of e-mails through the SMTP servers and clients.
