Prevent a message from be deleted but not from be moved

[Bruno Galindro da Costa]

Is it possible to prevent a message from be deleted but not from be moved
to another mailbox via ACL?

I need this because I'm using antispam plugin with the mailtrain backend.
It calls a script every time a message is moved to/from a monitored spam
mailbox. But, if the user deletes a message from the spam folder, the
script is executed with the option to train the antispam to consider that
excluded message as a non spam.

So, what I need is to prevent the user from delete a message from the spam
mailbox, but I want to permit the user to move a menssage from the spam
mailbox to another mailbox.



-- 
Att.
Bruno Galindro da Costa