Atmail can't send mails

[NEW Visions]

When I try to send an email it shows these message:

Could not send message to SMTP server. Check you have access to send messages via the server and that all To/CC/BCC addresses are valid\nError: SMTP Server rejected email. Returned:530 Authentication required

Any idea???? It happens in all my sites..... plesk 9.3, CentOs, postfix.

 

[[QT]Bender]

Go to /var/www/atmail/libs/Atmail/ modify Config.php and check that 'smtphost' variable equal to 'localhost':

'smtphost' => 'localhost',