The POP3 Client Lua Script is called POP3CLT.LUA and is edited in Settings → Scripts. This script is called whenever VPOP3 runs a POP3 session to download messages from a remote POP3 server.
VPOP3 will call the following Lua functions in the script at the following times:
ProcessMessage(“<mailfrom>”, “<subject>”, <recipient list>, <current actions>, <message MIME structure>, <message size>, <attachments>)
This function is called by VPOP3 when a message has been received by the SMTP service.
This function should return <new actions table>, <results string>
In this function the VPOP3 ProcessMessage helper functions can be used.