SwiftMailer problem

I use SwiftMailer in my PHP script to send emails upon HTML form submission.开发者_StackOverflow On the test server it all works fine. On the production server (different host) it gives me this error message:

Parse error: syntax error, unexpected T_CLASS in /home/alkal5/public_html/html/swift-mailer/lib/classes/Swift.php on line 18

What could it be? Thank you!

Have you checked the From and To setting and if both are OK then Please check the new server's email settings.