Directory Opus 8 includes a simple email (SMTP) client that can be used to send files via email from within Opus itself.
The 'To' field in the "New Message" window contains a drop-down list of email addresses. This email list comes from the Windows Address Book (WAB). This is the address book that Outlook Express uses, however Outlook (the full version included with Office) has its own address book that is separate from the WAB.
It is possible to make Outlook share its address book with the WAB, and in doing this, have your Outlook contact list available in the Opus email client.
Please view the instructions here on how to do this.