Here's a nice surprise that will make many Windows Mobile folks happy. It appears Redmond is serious about WM6.5.3, including now adding new features to Outlook (see our previous WM6.5.3 coverage here).
Threaded email has been the holy grail for many and for good reason. Being an "Exchange centric" operating system, Windows Mobile has a lot riding on its image as the premier business (and more and more consumer) email machine. Seeing as Google has left us high and dry for their Android platform, it only seems fitting that Microsoft fills the gap, as nothing beats native support.
Coming from the WM6.5.3 build 23517 (or 23515, there is some issue there), the Outlook client features a "Conversations" button near the top that gives different options for sorting (From, received, subject, etc.).
Messages act just like in Gmail: they are organized by a single topic, opening up the meta-message will reveal all the email in response. There is also about three lines of text to preview the message, saving you time from having to open up every message.
Overall the system is very efficient and a huge win for an added feature. Granted, we would have like to have seen this like yester-year, but we'll take what we can.
Update: to clarify, this is not Exchange 2010 dependent. It will work with your regular Gmail account or other services. It is the default sort option in Outlook, built into its core and independent of any Exchange account.
[thanks to A1jatt for the ROM]