[Users] Permanently decrypt an encrypted message

[Johan Vromans]

Hi,

When I receive (PGP)encrypted messages, I need to input my PGP key and then
I can read the message. When I close the message, the temporary decryption
is gone and the message remains encrypted in the mailbox. 

While this is good for some messages, it is not necessary for some other
messages. Once they survide the trip through the hostile internet and
arrive save on my servers they can be decrypted and may be kept decrypted.

I've searched the claws and plugins documentation but it seems that this
functionality is not provided by claws and/or the PGP plugins. 

How can I permanently decrypt an encrypted message?

-- Johan