When you type a letter/character in the To/Cc/Bcc field in Message window in Outlook, it automatically displays a drop down list with all contacts beginning with the letter/character. That’s the autocomplete cache. 

Sometimes, the autocomplete cache may get corrupted and you need to clear them.

Outlook for Windows

In Outlook:

  • Open Outlook.
    • Outlook 2010/2013/2016: On the Home page, click New Email.
    • Outlook 2007: Click New > Mail Message.
  • Type one or more letters of the recipient name or address; this will show memorized (cached) entries in a drop-down list.
  • Use the arrow keys on your keyboard to select the entry to be deleted. With the entry highlighted, press the DELETE key on your keyboard. Or you can click on the cross sign with your mouse.
This removes the entry from your autocompletion cache.

     

      Outlook for Mac

      In Outlook for Mac 2011/2016:

      • Open Outlook and click New email.
      • Type one or more letters of the recipient name or address; this will show memorized (cached) entries in a drop-down list.
      • Use the arrow keys on your keyboard to select the entry to be deleted. With the entry highlighted, press the DELETE key on your keyboard. Or you can click on the cross sign with your mouse.
This removes the entry from your autocompletion cache.


      Outlook Web App

      In OWA:

      • Click New (or New > Message)
      • Type one or more letters of the recipient name or address; this will show memorized (cached) entries in a drop-down list.
      • Use the arrow keys on your keyboard to select the entry to be deleted. With the entry highlighted, press the DELETE key on your keyboard.