This method will guide you to open the folder containing the Outlook auto-complete list, and then copy or export these files from the folder.

1. Double click This PC on the desktop to open the file explorer, and display hidden files and folders with checking the hidden items option on the View tab in Windows 8/10. See screenshot:

Note: If you are working in Windows 7, Please: (1) double click Computer on the desktop to open the file explorer; (2) click Organize > Folder and search options; (3) check the Show hidden files, folders, and drivers option and click the OK button in the Folder Options dialog box. See screenshot:

2. Paste below folder path into the Address box in the file explorer, and press the Enter key.

Folder path of Outlook Auto-complete list: %username%\AppData\Local\Microsoft\Outlook\Roam Cache

Now the folder containing Outlook auto-complete list is opening. The DAT files whose names begin with Stream_Autocomplete are Outlook autocomplete list files.

2. Select all Outlook auto-complete list files, right click and select Copy from the right-clicking menu. See screenshot:

3. Go to the destination folder you will paste the copied Outlook auto-complete list files, and press Ctrl + V keys simultaneously to paste them in the folder.

Easily export senders and recipients from emails and add as contact group members in Outlook

Normally, we can copy a sender or a recipient from an email, and then add it as a contact group member with Add Members > From Address Book, and it seems no way to add multiple emails' multiple senders or recipients into a contact group in bulk. But, with the excellent Add to Groups feature of Kutools for Outlook, you can easily add multiple emails' senders or recipients into contacts groups in Outlook with several clicks only.

Clear auto-complete cache in Outlook

Disable auto-complete name suggesting in Outlook

Remove and empty auto-complete list from Outlook