You should not use the Execute Query statement...as that is suppose to be used with select statements...or other statements that are ought to return record(s) from a given database.
When updating or deleting records, you should use the Execute Update method. for example
Once you've executed the above statement, you will get an integer value indicating the number of affected row(s)
affectedRecords= st.executeUpdate("DELETE FROM email WHERE email="+'"'+request.getParameter("email1")+'"');