Feature request: Add an Event when an Email is read

[Apflkuacha]

It would be great to have a possibility to execute a command or an alert if a Email message is read. So in addition to a event when a mail is received, I want to have a event when the mail is read. In my case I want to update the Unread-Messages counter in the taskbar.

[shanness]

I'd love this, but for other reasons. Basically I've got a script that does slack notifications on important emails, and would like to be able to trigger reminders if it's not read say a day later (just adding the use case).

[jenschurchill]

I am writing a python script to integrate Mailbox-Alert with Gnome4's libnotify, and this feature would allow that integration to remove alerts when read. Big +1.