firefly-iii/firefly-iii

use Illuminate\Bus\Queueable;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;

class NewIPAddressWarningMail extends Mailable
{
    use Queueable, SerializesModels;

    public string $host;
    public string $ipAddress;
    public string $time;

    public function __construct(string $ipAddress)
    {
        $this->ipAddress = $ipAddress;
    }

    public function build(): self
    {
        $this->time = now()->formatLocalized((string)trans('config.date_time'));
        $this->host = '';
        $hostName   = gethostbyaddr($this->ipAddress);
        if ($hostName !== $this->ipAddress) {
            $this->host = $hostName;
        }

        return $this->view('emails.new-ip-html')->text('emails.new-ip-text')
                    ->subject((string)trans('email.login_from_new_ip'));
    }
}

use FireflyIII\Events\DetectedNewIPAddress;
use FireflyIII\Mail\NewIPAddressWarningMail;
use Log;
use Mail;

class UserEventHandler
{
    //
    public function notifyNewIPAddress(DetectedNewIPAddress $event): void
    {
        $user      = $event->user;
        $email     = $user->email;
        $ipAddress = $event->ipAddress;

        if ($user->hasRole('demo')) {
            return; // do not email demo user.
        }

        $list = app('preferences')->getForUser($user, 'login_ip_history', [])->data;

        $pref = app('preferences')->getForUser($user, 'remote_guard_alt_email');
        if (null !== $pref) {
            $email = $pref->data;
        }

        foreach ($list as $index => $entry) {
            if (false === $entry['notified']) {
                try {
                    Mail::to($email)->send(new NewIPAddressWarningMail($ipAddress));

                } catch (Exception $e) { // @phpstan-ignore-line
                    Log::error($e->getMessage());
                }
            }
            $list[$index]['notified'] = true;
        }

        app('preferences')->setForUser($user, 'login_ip_history', $list);
    }
    //
}