[Enigmail] How Send "Partitioned" Messages?

[Kara]

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I was sent a key in the following format (with N = to the notation
indicated below).


uid  Dummy Name <dummy at dummy.xxx>
sig!     N   12345678 2007-10-29  [self-signature]
   Signature notation: preferred-email-encoding at pgp.com=partitioned

uid  Dummy Name
sig!         12345678 2007-10-19  [self-signature]
sig!  L      BDD13B90 2007-10-21  Kara Denizi
sig!     N   12345678 2007-10-29  [self-signature]
   Signature notation: preferred-email-encoding at pgp.com=partitioned


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When I try to send Dummy a GPG signed and encrypted message Enigmail
tells me the key isn't trusted although I have signed the free-form
userID.  However, unlike all other "untrusted" keys, if I check the box
to the left of the Enigmail key listing, it will send a signed and
encrypted message.

Question 1:  What do I need to do to have the key show up in the
             Enigmail listing as a trusted key?

Question 2:  Why would Dummy include such a notation with his
             self-signature rather than somewhere else (e.g.,
             perhaps within his key's preferences, etc)?

Question 3:  How can I indicate to GPG 1.4.7 via Enigmail that I want to
             send Dummy a "partitioned" rather than a PGP/MIME message?

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I'm using Ubuntu 7.10, GPG 1.4.7, Thunderbird 2.0.0.6, and Enigmail 0.95.5.


Timestamp: Sun 04 Nov 07, 1954 Local (UTC -0500)

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