Outlook and Office365 Webmail Showing the wrong name when searching for a contact in the "To..." field

Question

I've got a weird issue for one of my users.

It seems whenever he types a name in to the "To.." field of a new email, the search results shows the same repeated name for the list of suggested contacts, and then when you go to click on that name it populates with that person instead of the email of the person you typed in.

At first I thought it might have been a corrupt Outlook profile, so I deleted the pst file, rebuilt the Outlook profile etc., but it was still happening. Then I noticed that when he logs in to webmail, the same issue occurs. It's almost like he's got a corrupt address book on his exchange mailbox or something.

Here's some images so you can see what I mean:

Answer 1

Outlook remembers every address you enter in the To, Cc, and Bcc fields of an email message. Then, when you enter the first few letters of a name or email address, Outlook automatically suggests contacts that match.

If Outlook remembers mistyped and old contacts that you don't want to appear in the autocomplete list, get rid of those entries.

You can refer to this link to clear the autocomplete list: Clear the AutoComplete list

Answer 2

Try this:

With the list shown,
use CURSOR DOWN to move into it, by that only selecting the first entry.
Now hit Delete and it should disappear.
Repeat for all entries you wish to remove.

I suspect the list is the same email, but shown multiple times due to some tiny difference.