There are some known issues with Acrobat X and Outlook. These issues are as follows (taken from the Known issues documentation):
If Outlook is online with Exchange (cached Exchange Mode OFF), then PDFMaker can only convert 249 mails through selection. All the mails after that are skipped with Status "Unable to open secured message."
- You can open messages in Outlook in the same session where PDFMaker conversion through selection had failed.
- Folder conversion works fine. PDFMaker successfully converts 10000 mails in an online folder on exchange server.
- Tested for Outlook 2007, Outlook 2003, and Outlook XP. Same behavior irrespective of outlook version.
PDFMaker should be able to convert up to 1000 mails through selection with Cached Exchange Mode OFF.