How to send to BCC address when using PHPMailer to format MIME message for Gmail API?

Question

I am using PHPMailer to build an email message. I am using PHPMailer only for MIME message formatting, not sending.

I then extract the raw message from the PHPMailer object before passing it on to the Gmail API for processing.

//Create a new PHPMailer instance
$mail = new PHPMailer;

//Tell PHPMailer to use SMTP
$mail->isSMTP();
$mail->IsHTML(true);

//Disable SMTP debugging
// 0 = off (for production use)
$mail->SMTPDebug = 0;

//Set who the message is to be sent from
$mail->setFrom("[email protected]", "From Name");

//Set an alternative reply-to address
$mail->addReplyTo("[email protected]", "Reply Name");

//Set to address
$mail->addAddress("[email protected]", "Some Name");

//Set CC address
$mail->addCC("[email protected]", "Some CC Name");

//Set BCC address
$mail->addBCC("[email protected]", "Some BCC Name");

//Set the subject line
$mail->Subject = "Test message";

//Set the body
$mail->Body = file_get_contents("/messagestore/some.html");

//Attach a file
$mail->addAttachment("/messagestore/some.pdf","some.pdf","base64","application/pdf");

//generate mime message
$mail->preSend();

//get the mime text
$mime = $mail->getSentMIMEMessage();

//do the google API dance
$newMailMessage = new Google_Service_Gmail_Message();
$data = base64_encode($mime);
$data = str_replace(array('+','/','='),array('-','_',''),$data); // url safe
$newMailMessage->setRaw($data);
$gmailService = new Google_Service_Gmail($google_client);
$gmailService->users_messages->send('me', $newMailMessage);

According to PHPMailer docs, CC and BCC only function for sending in the Win32 environment.

However, my MIME formatted messages transmit successfully via the Gmail API to the "TO" and "CC" addresses, but not the "BCC" address.

To summarize, When I send email using this code and I provide a 'BCC' address to the Gmail API, I do not see 'undisclosed-recipients' in the sent message header, and the message is not transmitted to the BCC address.

When I send email using the gmail web interface and I provide a 'BCC' address there, I do see 'undisclosed-recipients' in the sent message header, and the message is transmitted to the BCC address.

Does anyone know of a workaround for this issue?

from what I know, BCC address won't be in the sent message's raw header. By that recipients won't see the address in BCC when they got the mail — Hoàng Long
Yes, but in this case the TO and CC transmit successfully while the BCC doesn't. — cloudxix
It's strange then. I think "To: undisclosed recipients" is NOT part of the protocol, usually the mail server auto put it there if there is nothing in the TO and CC field. But you have addresses in the To and Cc field, so it will not appear. Have you check the spam folder of your bcc recipient's address? — Hoàng Long
I am in development so I checked the BCC recipient email account and the message was not there. I am testing with a 'free' google apps for business account. the production account is a paid account. i suspect that perhaps google will not let me send BCC email from a free account. I will test and report back — cloudxix
The 'undisclosed-recipients' string is an entirely arbitrary name for an empty address group. It has no particular meaning. — Synchro

MCToon MCToon · Accepted Answer · 2015-04-15T21:55:47

PHPMailer will track the BCC recipients internally and if you were to send the message with PHPMailer it would specify the BCC recipients during the SMTP envelope.

However, when you extract the raw message from PHPMailer you lose the internal recipient list that PHPMailer was tracking. The raw message does not include the BCC information. The To: and Cc: headers will include the appropriate recipients and the GMAIL API probably uses these headers to infer the intended recipients.

To add in the BCC recipients you will need to use the GMAIL API to add these recipients before sending the message.

You didn't provide your GMAIL API code but it might follow this outline:

$message = new Message();

# construct message using raw data from PHPMailer
$message->setSubjectBody(...);
$message->setTextBody(...);
$message->setHtmlBody(...);

# *** add the BCC recipients here ***
$message->addBcc("[email protected]");

# send the message
$message->send();

How to send to BCC address when using PHPMailer to format MIME message for Gmail API?

3 Answers