A lot of the annoying Outlook aspects can actually be controlled from the Inbox settings. The general approach is to disable all the "smart" feature they tried to add.
First click on the settings icon (top-right-corner) then "View all Outlook settings".
In layout:
- Don't sort my messages
- Show email grouped as conversation
- Hide deleted items
- Reading pane at the bottom
- Don't show date headers in message list
In compose and reply:
- No "joyful animation" (what were they thinking...)
- No quick suggestion
- So suggested replies (ugh so creepy)
In Rules, you can set some nice filters, for example redirect all mails from *@yammer.com!
In Message Handling:
- "Mark displayed items as read as soon as they are selected" !
Outlook's layout uses way to much white space, which wastes a ton of vertical space. There is no way to change the density, like in GMail...
So here is the css trickery I've used, which could break any day. It shrinks the message previews in the middle and the mail folders on the left. There are probably other areas to tweak but I've found this combination "good enough".
So, add in chrome/userContent.css of your Firefox profile:
div[role="complementary"] div[role="option"] > div > div > div > div {
height: 20px !important;
}
div[role="region"] div[role="tree"] div[role="treeitem"] {
height: 20px !important;
}