Have a user that started having problems with a few, (not all), of her personal distribution lists. User states that she never had problems with message delivery until last week. Some members of various personal distribution lists do not get the email she sent. When I open the list and click on a member, sometimes that members Contact file opens...sometimes just the email properties opens...and sometimes she gets the following message: "Could not find contact <contact name>. It may have been deleted or moved from it's original location. Would you like to remove it from the list?"
As near as I can tell the members email address is an actual internet address as opposed to an "internal domain address" issued by Exchange Server, (2003). All of the members\recipients not getting her emails are internal members on the domain.