Find rows that have the same value on a column in MySQL

In a [member] table, some rows have the same value for the `email` column. login_id | email ---------|--------------------- john | john123@hotmail.com peter | peter456@gmail.com johnny | john123@hotmail.com ... Some people used a different `login_id` but the same `email` address, no unique constraint was set on this column. Now I need to find these rows and see if they should be removed. What SQL statement should I use to find these rows? (MySQL 5)