When Windows Mail suggest a previously mistyped (or deprecated) address, you can avoid the error by carefully steering around the misguided completion — or delete the address no longer needed.
Delete an Address from the Windows Mail Auto-Complete List
To remove an address from automatic completion in a Windows Mail email's address field:
- Start typing the address in a new email's To: field.
- Use the Down and Up arrow keys to highlight the address in the auto-complete list.
- Press Del.
- Address the email to yourself and click Send.
- Of course, you can use the open email to compose a regular email, too. Make sure you do not simply cancel composition, though.
You can also turn off auto-completion altogether in Windows Mail.

