CommandListservMatcher is the matcher that pairs with the
org.apache.james.transport.mailets.CommandListservManager It checks to see if the request is intended for the ListservManager, but doesn't guarantee that it is a valid command.
Matches mail with a header set by Fetchpop X-fetched-from
fetchpop sets X-fetched-by to the "name" of the fetchpop fetch task.
This is used to match all mail fetched from a specific pop account.
This Matcher determines if the mail contains the attribute specified in
the condition and if the value answered when the method toString() is
invoked on the attribute is equal to the String value specified in the
condition.
This Matcher determines if the mail contains the attribute specified in the
condition and that attribute matches the supplied regular expression,
it returns all recipients if that is the case.
Note: as it is not possible to put arbitrary objects in the configuration,
toString() is called on the attribute value, and that is the value matched against.