A lot of times people at the workplace try creative ways to claim ignorance about important matters…  Excuses like “I didn’t get your email” is one that seems to come to mind.  In Outlook 2007 you can easily resend the message in question.

With the mail message you sent open, in the Actions group click on Other Actions and scroll down to Resend This Message… 

Click on Send. While your message is open you can also choose to add recipients.

At this point you can also add or remove attachments.  Using this feature only allows you to resend one message at a time.  You will need to open each message separately and follow the previous steps.