Support HTTPS APIs (eg Resend) for sending emails

I have deployed listmonk on Railway on a Hobby plan. On the Hobby plan, Railway blocks all outbound SMTP ports. However, there are some services like Resend that allow sending emails over HTTPS API rather than SMTP. It would be great if listmonk supported this.

Railway docs about blocked ports: https://docs.railway.com/networking/outbound-networking#email-delivery Resend outbound mail API: https://resend.com/docs/api-reference/emails/send-email