Hi there,
I sympathize with you. At the time of MS Office 2003, PGP and MS Outlook were coexisting very well together.That is PGP Messaging and MS Outlook were working well with PGP/MIME and/or S/MIME as well (respectively).
Since MS Office 2007, PGP became erratic with Outlook with as a 'bonus' a complete disruption of the processing of the certificate X.509 in Outlook.
I was eager to find a solution, then I persistently pestered Microsoft, PGP/Symantec (Tom et al), McAfee, and the CA (Certification Authority for X.509) to no avail. Nobody seems to understand my problem.
Then I passed to MS Office 2010 (Hoping it was MS) but same story. I bought another laptop thinking about a hardware bug, same story.
Please note that during that time PGP and Windows Mail or Outlook Express were working well. Does it mean that MS Outlook is not compatible with PGP???
After several years of search I discovered that, if I want a communication X.509 based I exit PGP services. If I need a PGP messaging communication I avoid X.509. This is very clumsy as depending on which contact I am communiating with, and despite that I have still renewed my 2013 maintenance subscription with Symantec.
My configuration is: PGP Desktop standalone, MS Office, McAfee Total Protection, Windows Vista and 7 (No TPM nor Smart Card).
Still hoping for the PGP bug to be removed,
Best regards,
Bernard