[Users] Combining SpamAssasin and SpamReport in one single action

[Shai Berger]

Of note for this issue:

If I understand correctly, when a spam-handling plugin is installed,
the "mark as spam" action invokes the plugin's spam-handling
mechanisms; these usually include, among other things, moving the
message to a spam folder. If this happens, the message filename
parameter for the shell-command action (%f) may no longer be valid.

Just as you can define a shell-action and call filter-actions with
"%as{...}", you can do the opposite -- define a filter-action and call a
shell command using "exec...".

Up to 3.16.0, "mark_as_spam" was defined as a "final action" -- which
means, if a filter causes it to be executed, all further filtering
operations stop. I'm not sure how this would affect a shell-command
action using "%as{}"; and this has been changed in git, so if you
compile your own Claws from recent sources, this is not an issue.

Hope this helps,
	Shai.