Rated 5 out of 5 stars

per dotancohen el abr. 12, 2009 · enllaç permanent

A great extension, but missing Gmail's Killer Feature: threading with replies. For those looking for Gmail-style threading, vote for this bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=488044

@elPhilosoFee: Is this what you were looking for?