miltersexternal
Miltersexternal refers to milters that operate as external processes or services separate from the main mail transfer agent (MTA). They implement the Milter protocol to inspect and potentially modify messages during SMTP transactions. External milters can reside on the same host or remotely, communicating over Unix domain sockets or TCP, and are typically designed to be started, monitored, and scaled independently of the MTA core.
Architecture-wise, the MTA connects to external milters for specific filtering steps. The milters participate in a
Configuration and operation involve registering external milter endpoints in the MTA’s settings. The MTA negotiates protocol
Use cases for miltersexternal include modular spam and malware filtering, content policy enforcement, and header or