Hello I have used windows OS and Xampp control .. But I can't send a mail to my yahoo ID .I got a problem with PHP’s mail() , which was not sending any email messages out.I'm sending you my php coding. If you see any problem or any mistake in my code then plz tell me and suggest me how i can send And I did some changes in sendmail.ini [sendmail] ; you must change mail.mydomain.com to your smtp server, smtp_server=mail.mydomain.com ; smtp port (normally 25) smtp_port=25 ; if your smtp server requires authentication, modify the following two lines auth_username=username auth_password=drowssap ; if your smtp server uses pop3 before smtp authentication, modify the ; following three lines pop3_server=mail.mydomain.com pop3_username=username pop3_password=drowssap my code is here mail.html: <table width="400" border="0" align="center" cellpadding="3" cellspacing="1"> <tr> <td><strong>Contact Form </strong></td> </tr> </table> <table width="400" border="0" align="center" cellpadding="0" cellspacing="1"> <tr> <td><form name="form1" method="post" action="send_contact.php"> <table width="100%" border="0" cellspacing="1" cellpadding="3"> <tr> <td width="16%">Subject</td> <td width="2%">:</td> <td width="82%"><input name="subject" type="text" id="subject" size="50"></td> </tr> <tr> <td>Detail</td> <td>:</td> <td><textarea name="detail" cols="50" rows="4" id="detail"></textarea></td> </tr> <tr> <td>Name</td> <td>:</td> <td><input name="name" type="text" id="name" size="50"></td> </tr> <tr> <td>Email</td> <td>:</td> <td><input name="customer_mail" type="text" id="customer_mail" size="50"></td> </tr> <tr> <td> </td> <td> </td> <td><input type="submit" name="Submit" value="Submit"> <input type="reset" name="Submit2" value="Reset"></td> </tr> </table> </form> </td> </tr> </table> send_contact.php: <?php // Contact subject $subject ="$subject"; // Details $message="$detail"; // From $header="from: $name <$mail_from>"; // Enter your email address $to ='karthick_cse06@xxxxxxxxxxx'; $send_contact=mail($to,$subject,$message,$header); // Check, if message sent to your email // display message "We've recived your information" if($send_contact){ echo "We've recived your contact information"; } else { echo "ERROR"; } ?> Warning: mail() [function.mail]: SMTP server response: 550 The address is not valid. in C:\xampp\htdocs\test2\send_contact.php on line 12 ERROR See the Web's breaking stories, chosen by people like you. Check out Yahoo! Buzz. http://in.buzz.yahoo.com/ [Non-text portions of this message have been removed]