I have the same problem here, did somebody found a solution?
What is your Reader and Outlook version? I cannot reproduce this with Reader 11.0.2 and Outlook 2007 / 2010.
Outlook 2007 and Reader/Acrobat Pro X (10.1.6)
We have this problem in our organisation, here is our situation:
We use MS Office 2010 and MS Exchange server.
Some users have multiple mail profiles for specific email accounts that they can choose to open when they launch Outlook 2010.
If a user has launched Outlook using one of the other mail profiles that does not actually belong to their login account but they have permissions to use (ie. user Jane Doe [doej] has access to another Exchange email account of Primary Industries [primary]) , and then tries to use the "Send file as email attachment" button, it launches a new email and all looks good, says it is coming From: Primary Industries, user can click Send, but then the email is sitting in the users mail account Outbox (doej not Primary), and cannot be sent.
The PDF can be sent as an attachment from the Primary email account if the user first chooses to save the PDF, and then manually adds it to an email message they manually started to compose. This would be very time consuming for the users to do as they need to perform this function many times throughout the day.
It's as if the Adobe Reader application only wants to work with the logged in users mail account that belongs to them (ie. doej). I have even tried adding the other e-mail account in "Mail Setup - Outlook" in the Control Panel and setting this one as the Default E-mail account to use, but that hasn't helped.