message sent twice

You may be confusing AddAddress with AddReplyTo.

The AddAddress should only have emails, but it looks like you also put in the 'toName' in it.

See the example below:

$mail->AddAddress("<<email address to>>");
$mail->AddReplyTo("<<email address from>>","<<email name from>>");

look
this still does two emails

require '../../../phpMailer/class.phpmailer.php';
$mail = new PHPMailer();
$mail->Subject = "this is the subject";
$mail->From = "v-w-v@yandex.ru";
$mail->FromName = "axo_vlad";
$mail->Body = "hello it is the message";
$mail->AddAddress("nz.vlad@gmail.com"); 
$mail->AddBCC("vlad@axo.cc");
$mail->Send();

Select allOpen in new window

but this makes 4!!!!
without BBC stroke the code produces 4 emails!!

require '../../../phpMailer/class.phpmailer.php';
$mail = new PHPMailer();
$mail->Subject = "this is the subject";
$mail->From = "v-w-v@yandex.ru";
$mail->FromName = "axo_vlad";
$mail->Body = "hello it is the message";
$mail->AddAddress("nz.vlad@gmail.com"); 
 
$mail->Send();

Select allOpen in new window

Try just doing this (I tested this config before):

<?php
 
require("class.phpmailer.php");
 
$mail = new PHPMailer();
 
$mail->IsSMTP(); // send via SMTP
$mail->Host     = "<<smtpserver>>:<<stmpport>>"; // SMTP servers
$mail->SMTPAuth = true; // turn on SMTP authentication
$mail->Username = "<<uname>>"; // SMTP username
$mail->Password = "<<pword>>"; // SMTP password
$mail->From = "<<email address from>>";
$mail->FromName = "<<email name from>>";
$mail->AddAddress("<<email address to>>"); 
$mail->AddReplyTo("<<email address from>>","<<email name from>>");
$mail->WordWrap = 50; // set word wrap
$mail->IsHTML(true); // send as HTML
$mail->Subject  =  "Subject";
$mail->Body     =  "Body text";
$mail->AltBody  =  $mail->Body;
        
$mail->Send();
 
?>

Select allOpen in new window

i found the reason

after i removied checking script (see below) i started receive just one email as it needs to be...

why it can be so? it is interesting...

if(!$mail->Send())
{
   echo '<div align=\"center\" class=\"div\" style=\"margin-top:60px\">
		Message was not sent try again please
		</div>';
   echo 'Mailer error: ' . $mail->ErrorInfo;
}
else
{
//do whatever
}

Select allOpen in new window

I am unsure. There may be something in your logic that calls the section of code multiple times?

Do you understand that
if(!$mail->Send())
actually sends a copy of the message?

Sounds like you also have (had) another
$mail->Send();

i didnt know about it.  why is that?
 it doesnt make sence!