When you compose or reply a message, and type a letter in the "To" or "Cc…" box, the contact address starting with the letter will automatically pop up. It is very convenient and fast for you to get the correct contacts, but sometimes you may want to delete some of the contacts if the person already left the company, for example.
If you want to delete the address only once, please follow the steps below:
Step 1: Click "New Email" from the Ribbon to start a new email;
Step 2: Type a letter in the "To…" box and the contact list will pop up; a cross mark will show up at the end when you hover on the contact.
Step 3: Click the cross, the contact will be deleted from the list;
If you want to disable the "Auto-complete list" at all so no more contact will pop up. Please follow the steps below:
Step 1: Click "File" tab from the ribbon;
Step 2: Click the "Options" from the left navigation bar;
Step 3: Click "Mail" from the left navigation bar;
Step 4: Move down to the "Send Messages" section and uncheck "Use Auto-Complete List to suggest names when typing in the To, Cc and Bcc lines", and click "OK" at the bottom to close "Outlook Properties" window.
Step 5: If you want to delete all the contacts from the Auto-Complete list, please click "Empty Auto-Complete List".