<?php
#Адрес сервера
$SmtpServer="mail.***.ru";
#Адрес порта
$SmtpPort="25";
#Логин авторизации на сервера SMTP
$SmtpUser="username";
#Пароль авторизации на сервера SMTP
$SmtpPass="password";

#Класс работы с почтой
class SMTPClient
{
function SMTPClient ($SmtpServer, $SmtpPort, $SmtpUser, $SmtpPass, $from, $to, $subject, $body)
{
$this->SmtpServer = $SmtpServer;
$this->SmtpUser = base64_encode ($SmtpUser);
$this->SmtpPass = base64_encode ($SmtpPass);
$this->from = $from;
$this->to = $to;
$this->subject = $subject;
$this->body = $body;
if ($SmtpPort == "")
{
$this->PortSMTP = 25;
}
else
{
$this->PortSMTP = $SmtpPort;
}
}
function SendMail ()
{
if ($SMTPIN = fsockopen ($this->SmtpServer, $this->PortSMTP))
{
fputs ($SMTPIN, "EHLO ".$HTTP_HOST."\r\n");
$talk["hello"] = fgets ( $SMTPIN, 1024 );
fputs($SMTPIN, "auth login\r\n");
$talk["res"]=fgets($SMTPIN,1024);
fputs($SMTPIN, $this->SmtpUser."\r\n");
$talk["user"]=fgets($SMTPIN,1024);
fputs($SMTPIN, $this->SmtpPass."\r\n");
$talk["pass"]=fgets($SMTPIN,256);
fputs ($SMTPIN, "MAIL FROM: <".$this->from.">\r\n");
$talk["From"] = fgets ( $SMTPIN, 1024 );
fputs ($SMTPIN, "RCPT TO: <".$this->to.">\r\n");
$talk["To"] = fgets ($SMTPIN, 1024);
fputs($SMTPIN, "DATA\r\n");
$talk["data"]=fgets( $SMTPIN,1024 );
fputs($SMTPIN, "To: <".$this->to.">\r\nFrom: <".$this->from.">\r\nSubject:".$this->subject."\r\n\r\n\r\n".$this->body."\r\n.\r\n");
$talk["send"]=fgets($SMTPIN,256);
fputs ($SMTPIN, "QUIT\r\n");
fclose($SMTPIN);
}
return $talk;
}
}

if($_SERVER["REQUEST_METHOD"] == "POST")
{
$to = $_POST['to'];
$from = $_POST['from'];
$subject = $_POST['sub'];
$body = $_POST['message'];
$SMTPMail = new SMTPClient ($SmtpServer, $SmtpPort, $SmtpUser, $SmtpPass, $from, $to, $subject, $body);
$SMTPChat = $SMTPMail->SendMail();
}
?>

<form method="post" action="">
Куда:<input type="text" name="to" />
Откуда:<input type='text' name="from" />
Тема:<input type='text' name="sub" />
Сообщение :<textarea name="message"></textarea>
<input type="submit" value="Отправить " />
</form>

if ($SMTPIN = fsockopen ($this->SmtpServer, $this->PortSMTP))
{
$tval = 3; // максимальное количество времени ожидания ответа сервера в секундах
socket_set_timeout($SMTPIN, $tval, 0);
...

fgets ( $SMTPIN, 1024 );

$data = "";
while($str = fgets($SMTPIN,515)) {
$data .= $str;
# if the 4th character is a space then we are done reading so just break the loop
if(substr($str,3,1) == " ") { break; }
}