friend of mine sent PGP encrypted email from Outlook, but it's not decrypted on Evolution on Ubuntu Lucid. After some investigation it's showing that email's content-type is text/plain, but content is encrypted. on thunderbird it's prompting me gpg passphrase to decrypt it, and I can see decrypted message. asking my friend for proper configuration, he's saying that it's corporate settings so he cannot change anything.

Below are some headers:
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain;
 charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
X-TM-AS-Product-Ver: IMSS-7.0.0.3116-6.0.0.1038-17290.003
X-TM-AS-Result: No--1.097-5.0-31-1
X-imss-scan-details: No--1.097-5.0-31-1
X-TM-AS-User-Approved-Sender: No
X-TM-AS-User-Blocked-Sender: No