If you’re composing an email in Gmail, and you ask yourself, “Where did all those duplicate and incorrect email addresses come from?” You may need to take a couple of minutes for contact maintenance.
Go to contacts.google.com. In the left column, click More, then Other contacts:
To delete these unnecessary contacts, hover your mouse over the circle of the unnecessary email address and click its check box. After all addresses have been checked, click the three vertical dots in the upper right and select Delete:
Hopefully your Gmail autocomplete list contains fewer incorrect entries for the person you’re attempting to email.
Also published on Medium.