While troubleshooting why yet another email was stuck in my outbox, I noticed
that some recipients had their name and email address listed and some just
had their name listed. I had selected all of these contacts after clicking
Bcc via the "Search Names: Contacts" pop-up. When I went and looked at the
contact records where no email address was listed in the "Search Names
Contact" pop-up, the email addresses were in the correct field. I took
snapshots of different records to compare the differences between various
contacts. There aren't any.

When right clicking on different entries in the Bcc line, I noticed that I
could select Properties from the contacts who had email address entries in
the "Search Names: Contact" pop-ups and Outlook would open the contact
record. However, when I did the same for entries where Outlook just inserted
the name, I got a message that the entry was invalid. Of course, Outlook
does not give you an error message when you attempt to send this email; it
just remains in your Outbox.

Again, when comparing the contact records, there was no difference between
the the field entries. If I cut and paste the email address from the
"invalid" contact record and place it into the To/CC/Bcc fields, it formats
it correctly and doesn't regard it as invalid.