The reencryption as implemented by gpgol2 needs and option to put only encrypted mails into the new folder. This should also be enabled by default. The use case is that in many cases only a few mails in a folder are encrypted and it does not make sense to replace the f9lder just for this. Having side-by-side another folder which can be used to decrypt mails which are also found in the source folder is desired (by a customer).