I have a user that encounters an "Operation Failed" error when sending emails from the Drafts folder in Outlook 2013. The email she is attempting to send usually have attachments (.pdf files), and this has been going on for some time. I have installed patches for Outlook, turned cache mode off, and turned it back on again, as well as disabled add-ins that I thought might be causing it. Not sure if it might be an Exchange Server user profile issue, but it only seems to happen to this user.
The messages in question were not able to be saved to drafts, so they were not accessible In OWA. I have been trying to find a solution to this, but have only been able to deduce that the cause seems to stem from the user's reliance on Outlook templates that have been corrupted. I've never seen anything like this, and it doesn't happen to any of our other users.
Thanks for your help.