I have more to say, these notifications are the key feature of Paperflite service and I missed them strongly in Pitch.

For example, I sent a presentation to my client but he didn't open it. Then after a month when he was cleaning up his inbox he suddenly found my email and watched the presentation.

I should get a notification about it, because it means a lot for me. For example, I can make a call to this client the next day and I'm likely to get success.

This feature is very simple to implement, it is very important in paperflite (screenshot is in the attachment) and I hope you will make it soon.