An email client with the ability to create email threads from a template?

Question

gmail

I am looking for an email client (or a gmail add-on) that would be able to combine messages into one chain of letters according to a certain template.
How does gmail do it - in full compliance with the theme.
As necessary: ​​if there are three letters with subjects "#123 question", "123 answer", "#123 other" -
combine them into a chain "#123"
In standard clients, sorting by topic and grouping by date does not give the desired effect.
(So ​​far I have settled on Opera Mail, but my soul does not lie with it)
I would be grateful for any convenient options / alternative.