SMTP Server settings

We have added settings for the Email in ProjeQtOr in Global Parameters list
When changes are saved it prompts the settings are saved.
After navigating back to the same page the setting for SMTP server are again reset to "localhost"

The changes in PHP file are visible with new value. With sendmail file path it is added in the php.ini

When we try to send an email we get following error :

Not able to send mail to '0'.
Contact your administrator.

How do proceed to get the expected email sent from system ?

Regards,
DK