Sort first by Conversation topic, then by thread

[chyau]

Hi,

Sometimes, in long e-mail discussions, people do not always reply to the
latest reply, thus creating many threads within the same discussion topic.

For these e-mails, I would like to sort them first by conversation topic,
then by thread. Anyone knows how to do this ?

I have tried all the options in View settings, just couldn't get it to sort
the way I want.

Thanks,
chyau