stripping the encryption locally and storing unencrypted is fine, there is nothing standing in the way. You will want to keep signatures though (that's possible because mail is first signed then encrypted, and you only strip the outer layer), and use our trust model. You will also want to use opportunistic encryption and automatic key retrieval and distribution.
Posted Oct 28, 2011 10:56 UTC (Fri) by josh (subscriber, #17465)
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Personally, I'd like to do the opposite: encrypt email to my GPG public key upon receipt, so that I can store it on my IMAP server for convenient access from a couple of devices, without leaving it on my server unencrypted.