Warning/error generated when sending to CC or BCC without name

I'm running into the same issue with Drupal Commerce's use of sendgrid integration

I was able to quiet the message by taking that code and replacing it with the following:

$email_components = $this->parseAddress($mail_id);
$mail_cc_address = $email_components[0];
//if there was a name with the mail, use it—otherwise, use the email address as the name
$cc_name = $email_components[1] ?? $email_components[0];
$address_cc_bcc[mb_strtolower($key)][] = [
    'mail' => $mail_cc_address,
    'name' => $cc_name,
];

Running to the same problem, code in #3 solved my issue
I just make a patch for the code in #3

Thanks for your note, I reviewed the code in #3, and just created a patch for it.
Anyway, please review it and move it to RTCB as this will cause the whole email to fail if there is a CC or BCC with a capital case

Patch #4 is broken.

Fixes error getting flagged, but functionality is still broken.

If item contains both cc and bcc, the cc is clobbered by re-initialising array $address_cc_bcc, thus will not send the cc.

Removing the line

 $address_cc_bcc = [];

fixes. Just let the array get initialised when its first used.

      $address_cc_bcc = [];

      // Handle latter case issue for cc and bcc key.
      if (in_array(mb_strtolower($key), $cc_bcc_keys)) {
        $mail_ids = explode(',', $value);
        foreach ($mail_ids as $mail_id) {
          $email_components = $this->parseAddress($mail_id);
          $mail_cc_address = $email_components[0];
          // If there was a name with the mail,
          // use it—otherwise, use the email address as the name.
          $cc_name = $email_components[1] ?? $email_components[0];
          $address_cc_bcc[mb_strtolower($key)][] = [
            'mail' => $mail_cc_address,
            'name' => $cc_name,
          ];
        }

Created MR from attached patch and fixed #7

Changed to major as if both CC and BCC recepients are set, only later one is sent.

PR merged. Thanks!