GMAIL RFC 5322 Problem with send BCC's

[acedrummond]

I am sending a newsletter to a list of 300+/- people.

I have been doing this for a long time sending to each of the recipients, sleeping for 6 seconds between each and it takes a long time.
The sleep(6) is needed so that the hosting mail server is not overrun and hosting company stops processing. This takes about 40 minutes +/- assuming there are no hiccups along the way.

What I am trying to do now is use $mail->addBcc (loading it by looping thru my list) and when I do so any traffic going to a gmail.com address is creating a delivery event failure (message not delivered) "Message is not RFC 5322 compliant" - message blocked.

All other messages in my list get thru.

I do specify an $mail->addAddress that is the same as the $mail->setFrom

Is there a way to get gmail to accept this email that is to undisclosed recipients because I am using BCC's?

Are there other email providers with such restrictions? or are they planned in future?

My code:

$mail = new PHPMailer;

$mail->setFrom('anybody@xyz.org', 'XYZ');
$timestamp = date('Y-m-d');

    $mail->clearAddresses();

$mail->isHTML(true);

$sql ="select * from news_users where news_status = 'A' order by news_name";
    $result = $db->query($sql);

    // Add BCC from database
    $mail_count = 0;
    while ( $db_field = mysqli_fetch_assoc($result) )
          {
           $member_name  = $db_field['news_name'];
           $email                 = $db_field['news_email'];
           $news_seq          = $db_field['seq'];
           
           $mail->addBcc($email,$member_name);
           $mail_count = $mail_count + 1; 
         }          
// Sending copy any email sent to newsletter editor!     
$mail->addAddress('anybody@xyz.org', 'XYZ'); 

$mail->Subject = "VRCS NEWSLETTER Now Available";

// Body of the text either can contain default primary message
// replacement primary message and possibly additional message
    		
$mail->Body = $msg_text.$additional_text;

// Alt Body for those who cant tolerate HTML

$this_msg = $msg_text;
$this_msg = strip_tags($this_msg, "<b>");
$mail->AltBody = $this_msg;

$mail->AltBody = $this_msg;

if(!$mail->send())
  {
   echo "Mailer Error: " . $mail->ErrorInfo;
   exit;
  }
else
  {
   echo "Message has been sent successfully<br>";
  }

[Synchro]

I suspect your issue is that the php mail function might be mishandling the To header generation in the absence of named recipients, resulting in duplicate headers, causing the RFC5322 issue.

I suggest trying to use SMTP to localhost instead, which you should be able to do by adding this line:

$mail->isSMTP();

[acedrummond]

Thanks for your input.

See error message returned to host system.

It complains about 'duplicates'. (see attached)

If I send my list as a CC and not BCC it works properly. The BCC get addressed as 'undisclosed list' and that is the issue I am battling.

I just tried send via php mail function (STMP) instead and get the same results. It is gmails restriction as far as I can tell.

According to what I am reading RFC 5322 requires a To: to match the sender and it should work, but so far no luck.

delivery problem.pdf