Separate SMTP for each Event Crud in Laravel Backpack

Question

I'm working on a laravel backpack project. I have created an Event CRUD and each event has its own admin and SMTP details. Admin can sent invites to users for that event. I have already set sendgrid SMTP in my '.env' file and created a notification to send invites. Its working fine and sends invites notification to the users for that particular event through sendgrid SMTP. But I want notification to be sent out with that particualr event's SMTP.

I have searched a lot but couldn't find a feasible solution for that. Would really appreciate if anyone can point me into right direction.

Below is my Invites Notification class code:

namespace App\Notifications;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Notifications\Messages\MailMessage;
use Illuminate\Notifications\Notification;

class EventUserInvitation extends Notification
{
   // use Queueable;

    /**
     * Create a new notification instance.
     *
     * @return void
     */
    public function __construct($event_user)
    {
       $this->event_user = $event_user;

    }

    /**
     * Get the notification's delivery channels.
     *
     * @param  mixed  $notifiable
     * @return array
     */
    public function via($notifiable)
    {
        return ['mail'];
    }

    /**
     * Get the mail representation of the notification.
     *
     * @param  mixed  $notifiable
     * @return \Illuminate\Notifications\Messages\MailMessage
     */
    public function toMail($notifiable)
    {

        return (new MailMessage)
            ->subject('You are invited to ' .$this->event_user->get_event->name. ' at SpaceTo app')
            ->line('You have received this email to join the meeting created by ' . (($this->event_user->get_event->user) ? $this->event_user->get_event->user->name : $this->event_user->get_event->event_admin[0]->name) . '. Please click on the link below to proceed. ')
            ->line('If your browser doesn’t support automatic redirection please copy and paste the link to your browser address field.')
            ->action('Open SpaceTo App', url('/') . '/app')
            ->line('This email is an automated email please do not reply. ')
            ->line('In case if you have any questions please contact our support team support@spaceto.com')
            ->line('Have a great day.')
            ->line('Spaceto team. ');
    }

    /**
     * Get the array representation of the notification.
     *
     * @param  mixed  $notifiable
     * @return array
     */
    public function toArray($notifiable)
    {
        return [
            //
        ];
    }
}