I use Microsoft Outlook. I've been using Microsoft Outlook for approximately seven years, and before that I used tools like Microsoft Mail, and that weird forerunner to Outlook which included Schedule+. I think this entitles me to make contribute to a few design goals around the product and how it integrates.
Before Office 2003, Outlook was pretty much the only Office Suite application I cared about, whilst I used the others (Word, Excel, and Access) its Outlook that I said good morning to and Outlook that I said good night to. When Office 2003 was released OneNote really caught my eye, and its now my second most used Office application.
The thing that confuses me is that in Outlook we have this STUPID "Notes" section which is essentially no better than a NameValueCollection of strings. Now, I've gotta wonder, did the crew working on OneNote think - "hey we have this thing that is really good at managing the crap you'd usually have scattered all over your desk, lets embed it into Outlook and replace that cute, but generally useless Notes feature".
Did the Outlook heavies stomp on them? They are probably the same guys that have resisting putting an actual NNTP feature into the product for the last five years (sorry, outsourcing it to Outlook Express doesn't cut it).
Anyway - I think the next version of Outlook needs to rectify this. I'd like to see a nice little threesome, my data, Outlook and OneNote all playing in the same process space with lots of sharing of object handles. Is that too much to ask?
P.S. In between 1997 and now I did use Netscape Mail on a rusty old Linux box I had kicking around - it didn't last long and it didn't mean anything.