public function deleteAddress($username, $emailAddress, $isGUID = false)
    {
        $this->adldap->utilities()->validateNotNull('Username', $username);
        $this->adldap->utilities()->validateNotNull('Email Address', $emailAddress);

        // Find the dn of the user
        $user = $this->adldap->user()->info($username, ['cn', 'proxyaddresses'], $isGUID);

        if ($user[0]['dn'] === null) {
            return false;
        }

        $userDn = $user[0]['dn'];

        if (is_array($user[0]['proxyaddresses'])) {
            $mod = [];

            for ($i = 0; $i < $user[0]['proxyaddresses']['count']; $i++) {
                if (strpos($user[0]['proxyaddresses'][$i], 'SMTP:') !== false && $user[0]['proxyaddresses'][$i] == 'SMTP:'.$emailAddress) {
                    $mod['proxyAddresses'][0] = 'SMTP:'.$emailAddress;
                } elseif (strpos($user[0]['proxyaddresses'][$i], 'smtp:') !== false && $user[0]['proxyaddresses'][$i] == 'smtp:'.$emailAddress) {
                    $mod['proxyAddresses'][0] = 'smtp:'.$emailAddress;
                }
            }

            return $this->connection->modDelete($userDn, $mod);
        }

        return false;
    }