- ``--decrypt=(true|false)``
-
- If true, when encountering an encrypted message, try to
- decrypt it while reindexing. If decryption is successful,
- index the cleartext itself. Be aware that the index is likely
- sufficient to reconstruct the cleartext of the message itself,
- so please ensure that the notmuch message index is adequately
- protected. DO NOT USE ``--decrypt=true`` without
- considering the security of your index.
+ ``--decrypt=(true|auto|false)``
+
+ If ``true``, when encountering an encrypted message, try to
+ decrypt it while reindexing. If ``auto``, and notmuch already
+ knows about a session key for the message, it will try
+ decrypting using that session key but will not try to access
+ the user's secret keys. If decryption is successful, index
+ the cleartext itself.
+
+ Be aware that the index is likely sufficient to reconstruct
+ the cleartext of the message itself, so please ensure that the
+ notmuch message index is adequately protected. DO NOT USE
+ ``--decrypt=true`` without considering the security of your
+ index.