wp-includes/PHPMailer/SMTP.php:1483Set error messages and codes.
$messagestring$detailstringoptional''$smtp_codestringoptional''$smtp_code_exstringoptional'' protected function setError($message, $detail = '', $smtp_code = '', $smtp_code_ex = '') { $this->error = [ 'error' => $message, 'detail' => $detail, 'smtp_code' => $smtp_code, 'smtp_code_ex' => $smtp_code_ex, ]; }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/PHPMailer/SMTP.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.