wp-includes/PHPMailer/PHPMailer.php:2470Close the active SMTP session if one exists.
public function smtpClose() { if ((null !== $this->smtp) && $this->smtp->connected()) { $this->smtp->quit(); $this->smtp->close(); } }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/PHPMailer/PHPMailer.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.