The struggling Internet pioneer says that it will terminate all email accounts that have not been accessed within twelve months later this summer. Those email addresses will then be available for new users, the Los Angeles Times notes.
Users have until July 15 to access existing accounts.
After the deadline passes, other users can try and reserve email addresses freed up by the purge. The company will notify users who get a new email address by mid-August.
The number of accounts affected by the move remains unclear.
Earlier this month, Yahoo finally shut down its Yahoo Mail Classic service. The company introduced a new version last year.
Yahoo shares rose fractionally in Thursday morning trading.