Re: It's actually used a lot
@Sitaram In business, how many users actually choose their mail client though? Not many I'd bet, whether they like it or not.
I don't really care for the Notes client any more, it's got it's advantages but they're nowhere near enough to outweigh the problems. On the server/admin side though, I'd take it over exchange any day, even with it's flaws.
Not sure where you get that headers thing - I get a full sized window with everything in quite happily.
As for the sort by subject line, I couldn't say when it arrived, but if it really was that late then any half decent dev/admin team could have added it in - it's about 30 seconds work to make the change, and maybe a couple of minutes to apply it to the entire organisation, for a small/medium site anyway.
I tend to use iNotes webmail these days, but used the Domino back end with Thunderbird quite happily for a while, and have users that do so now without any problems. It's got a full IMAP server buried in there as well.