We recently installed Exchange Server 5.5. We have Outlook 98 clients. My problem is that when I send an email to addresses outside of the company, the From information is left off. I've sent email to an account on yahoo.com (and others), and when that account looks at the email, the From is blank. They are able to reply to the email fine, but when they are looking at the list of new emails it appears as possible junk mail because the From is blank. Any ideas? Exchange problem? Outlook problem?