Zend Mail - Email is not sent

[Theus]

I have a problem sending a registration email via zend_mail. The mail is transmitted only to mails that have a @gmail.com.\[code\]$email = "[email protected]";$mail = new Zend_Mail ();$mail->setBodyText ( 'some text' );$mail->setBodyHtml ( 'some text' );$mail->setFrom ( '[email protected]', 'MySite.net' );$mail->addTo ( $email, $email );$mail->setSubject ( 'test' );$mail->send ();\[/code\]If the user has another email provider the email is not sent.Any ideas?