As a LMTP user I want to execute the mailet container

Why?

LMTP is SMTP without a mail queue. Used inside a private network, with trusted hosts, the throughput is controlled upstream by the MTA/MX servers.

There is no sudden burst requiring buffering - buffering is done upstream.

James ships a LMTP implementation that mostly reuses the SMTP stack.

Today it delivers emails directly in people mailboxes.

The mailet container allows a declarative, modular and extensible processing upon email reception and is one of James selling points. Sadly today LMTP users cannot leverage its power...

How?

Write a `DataLineMessageHookHandler` that given an incoming LMTP transaction executes the mailet container.

Write a handler chain mirroring the default one, replacing the classical `DataLineMessageHookHandler` with the one executing the mailet container.

Write a unit test showing that upon an incoming LMTP transaction the mail is executed by a mock of the Mailet Container.

Finally write documentation concerning the handler chain.