[CobaltDragon]

Is there a way to make the OS/apps clear notifications that have been handled on another device? For instance, I have an IMAP email account...I get a notification that an email arrived on my Nexus 7 and on my 6P. I read the email on my N7 and the notification on my 6P never goes away on its own. On my WP, those notifications would go away the next time the email app sync'd to the server if I had read or deleted the email on my N7.

[Aquila]

The app developers have control over this. They can make it so reading a notification on one device clears it on all synced devices. What app are you using for email?

[hallux]

I agree with @Assassin Droid On my devices, it works as you hope/expect it to when I use the Gmail app.