The Mambo contact manager will not send out E-mails from customer notifications or from Contact Us Page on website. 

To correct this problem edit file /mambo/components/com_contact/contact.php

You will need to add two lines of code into this file.

1) Just above  code - if ( !isset( $op ) ) {

Add this line - $op = mosGetParam( $_REQUEST ,'op', '' );

2) Just above code - switch( $task ) {

Add this line - $task = mosGetParam( $_REQUEST ,'task', '' );

The edited section of the file should now look like.

$op = mosGetParam( $_REQUEST ,'op', '' );
if ( !isset( $op ) ) {
        $op = '';
}

//Load Vars
$con_id         = intval( mosGetParam( $_REQUEST ,'con_id', 0 ) );
$contact_id = intval( mosGetParam( $_REQUEST ,'contact_id', 0 ) );
$catid          = intval( mosGetParam( $_REQUEST ,'catid', 0 ) );

$task = mosGetParam( $_REQUEST ,'task', '' );
switch( $task ) {
        case 'view':
                contactpage( $contact_id );
                break;

Now save this file and overwrite the old contact.php file in this folder.  Your Email portion of Mambo will now be fully functional.