Why are email addresses missing in the Search Names pop-up?

[Malaise-from-Microsoft]

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.

 

[Russ Valentine [MVP-Outlook]]

Too little information to offer any assistance other than to observe that
autoresolution is not working for some of your Contacts. Most likely your
Outlook Address Book service has become corrupt. Reset it using the
instruction we post here frequently for your Outlook version.
We don't know your Outlook version or how you actually selected these
recipients. What you mean by "Search Names: Contacts" pop-up would need to
be defined. Changes you made to your Contacts or Outlook Address Book
configuration need to be specified for us to figure out where your problem
arose.