使用Phpmailer发送邮件，仅限BCC，隐藏TO标题字段

I'm using Phpmailer to send an email to multiple accounts using BCC.

I don't want "To:" field to be seen among the headers, but I think it is mandatory, because if I omit it I got this error:

Email error: You must provide at least one recipient email address

As a workaround I use my sender email under

$mail->addAddress (sendermail@domain.com);

but I'd like to send only BCC recipes.

Is it possible to do so or must I loop through all the emails recipe and send them one at a time?

Thank you in advance.

You can use undisclosed-recipients:;

$mail->AddAddress("undisclosed-recipients:;");
$mail->AddBCC(bcc@email.com); //there may be foreach loop

PHPMailer deals with this for you automatically. Just don't add any to addresses (i.e. don't call addAddress()), and add some BCC addresses:

$mail->addBCC('user@example.com');
$mail->addBCC('user2@example.net');

PHPMailer will automatically set the to header to the empty undisclosed-recipients:; group.