Newbie "addressee" question

I recently transitioned from Eudora to Outlook 2003 so there are some elementary operational details that have not yet entered my brain. I would appreciate a bit of help:

Sometimes when I begin typing an addressee's name in the "To" field, I get a display of choices. For example, if I type "Ca ", all the names beginning with Ca are displayed. Fine. Just what I expect.

But sometimes nothing appears. I can type in a partial name or even a complete name of an existing Contact but Outlook doesn't recognize it. For example, I have friend named "Kyle" and I have designated "Kyle" as his display name. Also, "Kyle" is the first part of his email address. Yet if I type "Kyle" into the "To" field, Outlook doesn't recognize it. This happens with other contacts, as well. But not all of them. Sometimes Outlook recognizes a name as I begin to type it and gives me good choices and sometimes it doesn't. Does anyone have any idea what's up?

TIA.

 

That works

Yes it does work. Thanks for that diagnostic. Does this mean that Outlook requires that an email be sent to each Contact before it will recognize them this way?

Once again...thanks for taking the time.