Being stuck with Outlook due to corporate inertia, most days i run into simple silly things that have been inconvenient for years:
- non standard shortcuts (what modern windows app doesn't use Ctrl F for Find which you would think would let you search an open email for text except it does something else!
- fragmented unintuitive disttribution of functions over tabs
- remarkably unhelpful use of space in the inbox views, such that columns rarely show enough of what you need to see
- annoying assumptions (eg typing a user name into the inbox search defaults to using From: when i frequently need to search with it as To: when I've got folders of email where I'm a co-recipient and need to search who the mail was address to)