New feature: undisclosed-recipients

Another feature request that users have asked for over the years is the ability to send emails with "undisclosed-recipients:" showing in the To: field.

They want to put their distribution list in the Bcc field with an empty To field to minimize the load on the server. Sending individual emails means the server has to loop through and send each email individually ... that can really impact server loads and the amount of time to send to mailing lists.

All three email transport classes (PHPMailer Pro, PHPMailer Lite, and PHPMailer Mini) will get the new feature.

The way it works is simple and intuitive. Add your recipients to the Bcc property with:

$mail->AddBcc("john.doe@example.com" => "John Doe"); // you can loop through and add all your recipients this way, or as a multi-dimensional array

You can either omit $mail->AddRecipients or set it blank with $mail->AddRecipients("");

To be clear, the email transport class will add "undisclosed-recipients:" to the To: field.

With this feature, only one email gets sent out with multiple BCCs that will not display to other recipients.

Be aware, there can be a penalty for this. Some spam filters may increase the overall spam score. Depending on your other email parameters, your email may be picked up as spam. It's worth testing before sending the actual campaign out.

PHPMailer Pro and PHPMailer Lite will now have three unique features:

• Add copy of email to your IMAP Sent mailbox (option)
• Add copy of embedded image as a downloadable (clickable) image (option)
• Transport emails via BCC with "undisclosed-recipients:" in To field

PHPMailer Mini will have one unique feature:

• Transport emails via BCC with "undisclosed-recipients:" in To field

The "undisclosed-recipients:" feature will be in the next release of all three email transport classes.