XF 2.1 Force notifications when people forgot to read message

[Mr Lucky]

One of my forums involves a lot of elderly people who don't always understand how things work, so they may get a notification about a message in a forum they are watching, but not actually read that message. They then no longer get notifications until they go back to that thread (I think that's how it works)

You will not receive any further emails about this thread until you have read the new messages.

So I would like to know if there is a way that they continue getting notifications even when they don't list the forum to read the message they got notified about.

Is this possible? Any add-on?