Outlook 2007 - A Tormented User

Hello
I had hopes that our endusers would learn how to use their applications. Here is Brandon with a serious complaint. I don't know what to do.

Brandon: I 'm reaching peak frustration: I have spent the past hour and a half trying to send an e-mail to a bcc group of about 50 recipients. First, I used the address book: disaster -- once I hit Send I got a bunch of prompts that it didn 't recognize names (that Outlook itself had drawn from auto-address!). Resolved all problems, then found said e-mail in one of my several Draft boxes from which it would not send; some sort of outbound error. Had to -re-create the whole thing in a new message. Then I typed each address in full by hand ignoring all auto-prompts just to get the darned message to send, which it finally did.
My e-mail I sent was a deadline reminder e-mail. Now that I have hand-typed each address, I am getting responses like "Did I ever receive this?" which now makes me believe the original invitation never arrived at e-mails that Outlook didn 't recognize from [one of] my [multiple] address books.
Very frustrating. Multiple In boxes, a Draft box under a sectuib of Outlook I didn 't think I was using; and the ongoing and seemingly endless conflicts with my super-critical address book[s].
Brandon.

Let me know how I can help Brandon. Is this a corrupt Outlook? A reinstall? I am at a loss. Thanks for any advice !

I want to add that the user for this account is stating to this IT fellow - 'I don't want to hear from you...I have issues with Outlook. What I want you to do is fix it. Fix Outlook.'
Now that's a problem. The user, Brandon, gets no errors. I ran the Office Diag. Everything is perfect. I am certain Brandon is having difficulties and those difficulties are unpredictable. How can one fix Outlook 2007 if it generates no errors? I am thinking maybe I should setup a Thunderbird account for Brandon. Should I uninstall Outlook and reinstall ? I am certain that would do nothing to fix the issue. Thanks