May 26, 2018
Secure and efficient mail gateway
MeTA1 is a message transfer agent that has been designed with these main topics in minds
MeTA1 consists of five main modules of which only one runs as root
- mcp the main control program is similar to inetd8 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.