Outlook having trouble expanding email addresses?

Over the years something's been nagging at me, but I've never taken the time to diagnose it. Finally I just couldn't take it anymore, when on a brand new paved machine, I couldn't get Outlook to expand email addresses automatically when I send mail.

Know how Outlook usually manages to autocomplete names for you? I can type in “fritz”, and by the time I hit send, Outlook has expanded “fritz” to his full email address, usually along with a nice display name. But for a bunch of names this just doesn't seem to work. And if you press send, you're hit with a dialog that shows you that there is a duplicate entry in the address book for that person.

I finally got sick of this behavior and figured out a) what was going on, and b) how to fix it.

a) Your address book is just a special view on your contacts folder (if you're using Outlook like me, that is - in a corporate environment this may not be the case). You need to be aware that Outlook treats Fax numbers specially - your address book considers a fax number to be a first class citizen. So if I have Fritz's fax number in my contact card for Fritz, he'll have two entries in the address book (at least this is the case with the Business Fax number).

b) The solution I discovered (unfortunately I don't recall the link or I'd post it here to give the author credit) is to precede the fax number with some text. For example, change 123-555-1212 to Fax: 123-555-1212. Problem solved.

I personally don't use fax numbers to automatically send faxes, so this works for me, and I suspect it will also work for a number of you guys who have probably run into the same problem.

Hope this removes an iota of frustration from your day!