MeTA1 is an open source software project that provides a modularized MTA (Message Transfer Agent) consisting of five (or more) persistent processes, with four of them being multi-threaded. It has been designed to be secure, reliable, efficient and extendable. The project can be easily configured using a C-like syntax.
What’s in the package?
The software comprises of five main modules. In alphabetical order, they are MCP (the main component, a control program that is similar to inetd), which can be used to start all the other MeTA1 modules, SMTPS (the SMTP server that receives email messages), SMTPC (the SMTP client that can be used to send email messages), SMAR (the address resolver), which allows you to search various maps, including DNS, for email routing, as well as QMGR (the queue manager), which controls how the emails go through the SMTP server and the SMTP client. Keep in mind though, that only MCP runs as root!
How does it work?
Here's how MeTA1 works: a queue manager controls both SMTP clients and servers to send and receive email messages, a main control software starts the other processes and monitors their execution, and an address resolver offers lookups in various maps, including DNS, for mail routing.
Does it support by Linux box?
Yes, most probably, as MeTA1 is distributed as a universal source archive, which can be installed on any Linux kernel-based operating system where a GCC compiler and various essential build tools exist. It has been successfully tested on both 64-bit (x86_64) and 32-bit (x86) hardware platforms.
When interacting with MeTA1, it is very important to know that its configuration file is quite simple and resembles BIND 9 configuration files. In addition, the program comes with the libpmilter policy mail filter library, which is similar to the libmilter library from the sendmail project.