Comment 7 for bug 671746

In this case I vehemently posit that conversation (and not tree-threaded) is the "best" view for most of your average user who handles (replies to about 30-50) upto a hundred mails a day. There's a reason Gmail is so popular, and not many use pop/smtp clients to access it.. the interface provided by the web interface is very intuitive. Collating similar subject mails into one makes sense usability-wise, and saves screen estate, that would otherwise be littered with "Re: Re:" and "Fwd: Re: Re:" items.

Conversation-view is one thing that will guarantee a 100,000 users on the first release, because it is a much requested feature, that the incumbent Thunderbird and Evolution clients have not supported (look at the download numbers for the addons to thunderbird which provides conversation view). Postler could even put postbox-inc.com out of business.

~Anil