email sending function with email address validator.
sends HTML email, so you can style your email message with inline styles and everything you can do to a webpage.

“send email” makes use of the built-in PHP functions ereg( ), strtr( ) and mail( ).

01 <?php
02  
03 // checks the syntax of the emailaddress
04 function check_email($emaildddress)
05 {
06     $goodchars = '^[A-Za-z0-9\._-]+@([A-Za-z][A-Za-z0-9-]{1,62})(\.[A-Za-z][A-Za-z0-9-]{1,62})+$';
07  
08     $isvalid = true;
09     if(!ereg($goodchars,$emaildddress))
10     {
11         $isvalid = false;
12     }
13     return $isvalid;
14 } 
15  
16 // sends the HTML email 
17 function html_email($recipient,$subject,$message,$from,$replyto)
18 { 
19     $array = array("\'" => "'");     
20     $message = strtr($message, $array);   
21     $message = '<html><body>'.$message.'</body></html>'."\r\n\r\n";
22     $extra = 'From: '.$from.' <'.$replyto.'>'."\r\n";
23     $extra .= 'Content-Type: text/html; charset="ISO-8859-1"'."\r\n";
24     $extra .= 'Content-Transfer-Encoding: quoted-printable'."\n\r\n";
25     mail($recipient, $subject, $message, $extra);
26 }
27  
28 // use like this
29 // specify the address the mail will be sent from
30 $mail_sender = 'sender@example.com';
31 // specify the name of the sender
32 $mail_sender_name = 'example sender';
33 // specify the recipient email address
34 $mail_recipient = 'recipient@example.com';
35 // specify the subject of the email (no HTML here!)
36 $mail_subject = 'HTML email test';
37 // the body of the email - you can use HTML here
38 $mail_body = '
39 <h1 style="color: red;">Hello there</h1>
40 <p>this email should be styled HTML...</p>';
41  
42 // if email addresses are valid
43 if(check_email($mail_recipient) && check_email($mail_sender))
44 {
45     // send HTML mail with PHP
46     html_email($mail_recipient,$mail_subject,$mail_body,$mail_sender_name,$mail_sender);
47     echo '
48     <p>the email &quot;'.$mail_subject.'&quot; was successfully sent to '.$mail_recipient.'</p>';
49 }else{
50     echo '
51     <p>invalid email address - email was not sent</p>';
52 }
53  
54 ?>