We can send mail by Using mail() function.This is a PHP predefined function for sending mail.

Also we can send multiple attachment at the same time using php mail function and using php code for multiple files.

For sending multiple attachment we have to use MIME extenstion.

Also we have to create an array of file that we would like to send as an attachment along with mail.

Example: Below is the php script for sending multiple attachment.

<?php

    // array with filenames to be sent as attachment
    $files = array("file1.jpg","file2.pdf","file3.txt");

    // email fields: to, from, subject, and so on
    $to = "yourmail@mail.com";
    $from = "mymail@mail.com"; 
    $subject ="My subject"; 
    $message = "My message";
    $headers = "From: $from";

    // boundary 
    $semi_rand = md5(time()); 
    $mime_boundary = "==Multipart_Boundary_x{$semi_rand}x"; 

    // headers for attachment 
    $headers .= "\nMIME-Version: 1.0\n" . "Content-Type: multipart/mixed;\n" .   "
                 boundary=\"{$mime_boundary}\""; 

    // multipart boundary 
    $message = "This is a multi-part message in MIME format.\n\n" . "--{$mime_boundary}\n"
               . "Content-Type: text/plain; charset=\"iso-8859-1\"\n" . 
                 "Content-Transfer-Encoding: 7bit\n\n" . $message . "\n\n"; 
    $message .= "--{$mime_boundary}\n";

    // preparing attachments
    for($x=0;$x< count($files);$x++){
            $file = fopen($files[$x],"rb");
            $data = fread($file,filesize($files[$x]));
            fclose($file);
            $data = chunk_split(base64_encode($data));
            $message .= "Content-Type: {\"application/octet-stream\"};\n" .  

                        " name=\"$files[$x]\"\n" . 
            "Content-Disposition: attachment;\n" . " filename=\"$files[$x]\"\n" . 
            "Content-Transfer-Encoding: base64\n\n" . $data . "\n\n";
            $message .= "--{$mime_boundary}\n";
    }
    // send
    $success = @mail($to, $subject, $message, $headers); 
    if ($success) { 
            echo "
 mail sent to $to ! 
"; 
    } else { 
            echo "
 mail could not be sent! 
"; 
    } 

?>