Mail message hangs when Send to Recipient via Window

Each time I right click on a word file in Windows Explorer or use send to from with in word or execl and select Send to Mail Recipient, when I send the message it hangs. Explorer stays operational, as does Outlook, and Word. Despite that, it does reach the recipient, and appears in Sent Items. But the message screen itself hangs and stays there till I kill it. I'm using Outlook 2007 Pro installed by the OEM (Dell) and Windows XP Professional.