Hi,
You can use below step by step tutorial to connect mysql with php.You can connect mysql with php with below usages :
Mysqli

<?php
$host = “localhost”;
$user_name = “db_uname”;
$pass_word = “db_password”;

// Creating new connection
$con = new mysqli($host, $user_name, $pass_word);

// Checking for new connection
if ($con->connect_error) {
die(“Connection failed: ” . $con->connect_error);
}
echo “Connected successfully”;
?>

Hi,
you are not able to send email in php because you are not sending headers along with email.
Please try with below simple tutorial to send email in php.

<?php
$to      = '[email protected]';
$subject = $subject ;
$message = $message ;
$header = "From: [email protected]\r\n"; 
$header.= "MIME-Version: 1.0\r\n"; 
$header.= "Content-Type: text/plain; charset=utf-8\r\n"; 
$header.= "X-Priority: 1\r\n"; 

mail($to, $subject, $message, $header);
?>

Hi,make some section Transparent wherever you wants to add your Colors. i.e,

if you want to change notification color then you can change like this :

 .setColor(your_color_resource_here)
 

CAUTION: setColor is working in Lollipop not any other version you need to check for the same.

if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
    Notification notification = new Notification.Builder(context)
    ...
} else {
    // Lollipop specific setColor method goes here.
    Notification notification = new Notification.Builder(context)
    ...
    notification.setColor(your_color)
    ...            
}

You can also make this happen by using Lollipop as the target SDK.

You can find more details for NotificationIcon at Google Developer Console Notification Guide Lines.

Preferred Notification Icon Size 24x24dp

mdpi    @ 24.00dp   = 24.00px

hdpi    @ 24.00dp   = 36.00px

xhdpi   @ 24.00dp   = 48.00px