opigno can't send email reset password

Hi all. i have a problem this day when i try to access to my web page, opigno cant recognize me, i change manually via phpmyadmin the admin name for the original name (the name i was provide), but when i try to reset my password via opigno, it can't send me an e-mail, i try to test with another usernames and e-mails and work, but with my admin e-mail doesn't work. what i can do?