Knowledge base
Inspect and answer an incoming SMTP connectionplugin functionSeven functions on an incoming connection: its socket, whether it is encrypted, whether it is authenticated — and the ability to decide that last one.Read and rewrite the messageplugin functionNine functions that read and replace every part of an incoming message — including the whole job as JSON.Hand control back to the engineplugin functionThe three ways a plugin finishes: done, carry on, or try this again.The plugin's own stateplugin functionA slot where a plugin keeps its own state across calls.Read and classify an addressplugin functionThe address group: read the address as text, ask whether the engine considers it local, and change that answer.Share the engine's event loopplugin functionA plugin runs inside the engine's libev loop, and gets watchers and timers rather than threads.Write to the engine's application logplugin functionThe one output channel a plugin has: the engine's own log, at one of three priorities.