I'm trying to configure some automation when it comes to labeling my Gmail mailbox.
Currently, I want to apply label "X" to every new message that match the specific string "abc" and DON'T have label "Y".
The problem I'm facing is that whenever someone responds to old thread with label "Y", the filter is being triggered and this mail have to labels "X" and "Y".
TLDR: I don't want to label threads with specific label, but it is not working.
Best Answer
In Gmail, labels can be nested, so organized in a tree structure: As labels prepared in advance, as rather static objects, manually.
If I understand you correctly:
There is no such feature in Gmail, AFAIK.
I can imagine such feature, i.e. for notification emails from a ticketing systems like Jira or eBay... But I have never heard about such feature in Gmail. Not for/in any mail client at all.