[lug] gpg email

[karl horlen]

i've been reading up on GPG for email.  if i use this with tbird via the enigmail plugin i understand all but one aspect of it.  that being that the underlying email account is probably going to be IMAP and hosted by my isp or a public mail service circa hotmail, gmail, etc.  

1) so the question is, when i decrypt my messages, do they "only" get decrypted "locally" on my current system 'every time' i open a mail message or do they 'permanently' get decrypted and saved 'back to the imap folder' somewhat negating the whole concept of the encryption?  or do i have to 'permanently' download the message to a 'local' tbird folder and then decrypt?

hope that makes sense.  if i'm going to use GPG, i'd be doing it to make sure the plethora of email that's stored at gmail, isp, etc is archived there as encrypted and not decrypted.  otherwise it defeats the purpose of the encryption in the first place.

2) if i ever decide to change my key pair, which seems like it might be a good thing to do once in awhile, would i lose the ability to decrypt any of my archived mail sent to me via my public key or does the symmetric key that was sent with it, somehow get decrypted and stored in my archived mail?

hope that question made sense ;-).  in my current non gpg tbird, i've got about 3 years worth of email logged in local folders outside of imap.  if this was gpg'd email and i decided to change my keys, would i not be able to access any of that email?  or would i always need to have to keep all keypairs i ever generated?  is there anyway to keep it permanently UNencrypted since once it's archived locally and not on a public server somewhere, i may not care whether it's encrypted or not.

thanks