How to automatically change/delete labels in Gmail?

Question

gmail

Here is a case-problem:
I am discussing an important issue in gmail. There are 20 such topics at a time. And so I considered that the question was settled and assigned the label (label) "!Ready". It looks like this [screenshot] .
But it often happens that what I considered closed (sent a letter and thought it was in the bag), but they still answer me something! This means that the case is reopening.
Question: how to make it so that if someone replied to a thread, the tag would be removed?
PS. I know about Outlook, but I do not want to switch to it yet because of the bulkiness.

Answer 1

I work on a different principle.
I send chains on closed questions to Archived.
If a response arrives along this chain, it automatically goes to the Inbox.
Thus, I have only relevant chains in my inbox.
What you want is not in standard Gmail.
IMHO it is possible to write on GAE.

Answer 2

www.rememberthemilk.com/