Why is sending multiple email notifications upon form submission limited to 10 external email addresses?

Why is sending multiple email notifications upon form submission limited to 10 external email addresses?

When we built a notification form, we need to send it to multiple external stakeholders so that they are all aware of a potential situation. Our process is that they then "reply all" so that we keep the information chain cohesive and linear. Why is there a limit of 10? Is there a way that we can add more than 10 external emails?

Thank you!