Resolved php mail fails for regular users, works for root

[tkalfaoglu]

A test.php file stored at the customer's httpdocs folder produces nothing if the owner of that file is
username : psacln ... If the owner is root:root then the mail is delivered. The file is very simple:

<?php
mail('xxxxx@kalfaoglu.net','hello','test mail function');
?>

Sendmail is enabled both on server level and subscription level for that customer.
What else shall I check?
many thanks -t

 

[tkalfaoglu]

PS: The user in question does exist in the database.. likewise for the domain.
That is, this case is not the same as Mail send failure on Plesk server: "You are not allowed to use sendmail utility. REJECT"

 

[tkalfaoglu]

UPDATE: I disabled the use of sendmail server-wide.. then re-enabled it..
Now my test.php works - it sends mail as regular user!