To make this a bit more clear I will describe this with a few screenshot below:
We'll start off with opening a received email and pressing the Track button in CRM
This will then allow us to press the convert to Opportunity, Case or Lead, directly from Outlook. A very neat, and new function. It came with CRM 2011. In this example, I am selecting Case.
So, I tried it the old way. I sent myself another email, pressed the track in CRM button, and then instead of converting it directly from Outlook, i pressed the "View in CRM" button to open it in CRM.
I then converted it to a case from the ribbon menu from the CRM Email from by pressing the "To Case" button.
And by opening the CRM email form from the list shows it clearly:
The regarding field has been set properly.
This is a very unfortunate bug in CRM and I do hope Microsoft solve it quickly as the feature that CRM 2011 adds in Outlook by being able to convert emails to cases, opportunities and leads directly from the email form is very good but as all of you know who work close to sales or customer service people, their time is very precious and every click counts and new features that do not deliver as expected are always annoying to the user. So, until the bug has been fixed, make sure the users open the CRM form to convert the emails.
Update: Jukka Niiranen left a very informative comment to this posting below informing us that Microsoft probably will fix this bug in UR6 planned to be released in Jan 2012.
CEO, Chief Architect and co-Founder at CRM-konsulterna AB