Hi, I have been looking for the answer on how to address this error. But unfortunately couldn't find any. I have a Debian Lenny, and installed using the "Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (Debian Lenny), by Falko" It was a successful installation and configuration. But at the change_sqlpass plugin, wherein it is not included on the said tutorial, about activating the force_change_password_check_query, I activated this, and changing necessary entries: Code: .. $password_update_queries = array('UPDATE users SET password = %4, force_change_pwd = 0 WHERE email = "%1",) .. $force_change_password_check_query = 'SELECT force_change_pwd FROM users WHERE email = "%1"; //$force_change_password_check_query = ""; I added the "force_change_pwd" field on the users table. I activated this because I wanted my users to change their passwords upon login in special times. Necessary changes are successful, but I get this error afterwhich: Code: Warning: Cannot modify header information - headers already sent by (output started at /usr/share/squirrelmail/functions/page_header.php:32) in /usr/share/squirrelmail/functions/global.php on line 530 Warning: Cannot modify header information - headers already sent by (output started at /usr/share/squirrelmail/functions/page_header.php:32) in /usr/share/squirrelmail/plugins/change_sqlpass/functions.php on line 943 Does anyone had a solution for this?