Problem in User Registration

[errorme]

Hi,
I have website, created with symfony 1.4 (programmer can`t help me anymore)
Looks like good, but when i change password in mail via cpanel (example: info@mysite.com), when user has register, system do not send activate mail ( mail after success registration).
When i back old pass for info@mysite.com everything is ok!

How i can change password via cpanel from info@mysite.com mail account and when user was register, system send activation mail?