error !== null) { throw $this->error; } $this->submitted[] = compact('host', 'port', 'from', 'rcpt', 'data'); return 'Q' . count($this->submitted); } public function probe(string $host, int $port, string $tls, string $username, string $password, string $from, string $rcpt): array { $this->probed[] = compact('host', 'port', 'tls', 'username', 'password', 'from', 'rcpt'); if ($this->error !== null) { throw $this->error; } return $this->extensions; } public function mailHost(string $domain): string { return $this->mx[$domain] ?? $domain; } }