Click on the column heading of the column you want to sort by. You may need
to click twice as in mine clicking on Subject puts it in reverse order (Z-A)
but clicking twice sorts it (Z-A). Go to the View menu and select Threaded
to have the replies under their corresponding original posts.
If you're using Entourage 2004, the process is slightly different. If you
want to see the subjects listed in alphabetical order, like the above
process for Entourage X & 2001 will give you, go to View > Arrange By > Show
in Groups, and then go to View > Arrange By > Subject. I also like to see
threads arranged by subject, but I like to see the different threads in
chronological order based on the most recently set message. To do that,
I've set up a custom arrangement (View > Arrange By > Edit Custom
Arrangements). It looks like this:
Group items by: Subject
Sort groups by: Sent Newest on Top
Sort items within groups by: Sent Oldest on Top
Default display for groups: Expanded
I can then order any folder or newsgroup that way by opening it and then
going to View > Arrange By > My Custom Arrangement (right below the Edit
Custom Arrangements item). It sounds like you definitely want items grouped
by subject. You then have flexibility as to how you want to subject groups
ordered (the second option), and how you want the items within each group
sorted (the third option). Explore the options to see what works best for
you, save it, and then apply it to a folder.
In the future, please state which version of Entourage you are using.