New features:

• Pin/Unpin Email

• Snooze email

• Density has 3 choices instead of 2

• Can preview message body next to subject in message list (replaces 1/2/3 line message preview – see below)

• Board

• Integrates MS Loop cloud components

Features removed (in no particular order):

• Customize ribbon

• Ribbon cannot be hidden

• Preview 1, 2, or 3 lines of message body in message list

• Choose columns to show in message list

• Separation of categories from subject in message list

• Shared categories cannot have color

• Cannot “view source” of HTML emails

• Status bar

  • Item count, server connectivity status, zoom level, etc.

• Rearranging folders in folder tree

• Cannot set folder to show item count

• Outlook forms

• Notes view

• Folders view

• Folder pane cannot be “minimized” to show folders sideways

• “Share to Teams”

• “Send to OneNote”

• Find/replace within message when composing email (Ctrl+F)

• Outlook Today (although may be replaced with “My Day” or “Board”)

• PST file support

• Translate

• Search ribbon

• Advanced Search (Ctrl+Shift+F)

• Search Folders

  • “Unread Mail” in favorites is an example

• Cannot right-click and “Add to favorites” for shared mailboxes

• Reply with IM (opens Teams chat with sender)

• Copy email attachments

• Sort/Filter options greatly reduced

• Rules are far less capable

  • Can see, but not access/use better rules from old Outlook

  • Rule to move message to another mailbox

• OneDrive link does not honor policies and be hidden

• “To Do” opens in browser instead of within Outlook

• No contacts from shared mailboxes

• No print options in Mail view. Must open each message and print one at a time

• No print options in Contacts view

• “Clean up” mailbox

• Send/Receive/Sync Now

• Creating email signatures via script

• Recall email

• Resend email

• Work offline

• Quick Access Toolbar and Previous/Next email buttons when viewing a message

• Public folders must be manually added to favorites to see them

• Accessibility is basically gone

• Using Outlook without mouse/touch is not possible

• To Do bar (although may be replaced with “My Day” or “Board”)

• View Settings is extremely gutted. (old Outlook is insanely powerful here)

• Rich text format for composing email

• Voting options (replaced with browser-based MS forms)

• Does not use Word as email message editor, so these features are gone when composing email:

  • Styles, smart tables, thesaurus, find & replace, paragraph formatting, advanced character formatting, page color, effects, themes, smart art, word art, OLE objects, etc.

  • Set bullet type/style in bulleted list

  • Quick Parts

  • Right-click

• Does not use Word as description editor for calendar event entries. So, above features are gone here too

• Email composer does not support:

  • Message expiration

  • Hanging indents or tab customization

  • Reply-to alternate email address

  • Digitally signing or encrypting emails

• Auto pick time for creating meetings

• High importance & low importance tags for calendar events

• Dictation

• No way to open address book within “Create calendar event”

• Looking at Settings/Options reveals dozens (hundreds?) of missing options when compared to old Outlook

New features (from the comments):

• None

Features missing (from the comments):

• Alt-R and Alt-W hotkeys

• Not having Word as email editor:

  • Cannot put border or shading around inserted images

  • Can only select from a subset of Windows fonts

• Does not migrate quick steps from old Outlook even though they are stored on the server.

• Cannot open .EML or .ICS files

• COM and VTSO add-ins

• MAPI is gone. No more “Print PDF to email”, or other apps using email workflow

  • Can’t “share as attachment” from the other Office apps.

  • Mail merge using Word and Excel may not work

• Message Templates

• Unable to sort by name, then type in the name to go to that grouping.

• Custom follow-up reminders for email

• “Next 7 Days” Calendar view

• Tasks view

• Can’t delete attachments from emails and still keep the email

• Can’t save an attachment where you want, it goes to downloads

• Cannot setup multiple languages for spell checking within a message.

• Read Aloud (text-to-speech) is only available within Immersive Reader instead of right-clicking

• Right-click on message -> Find Related

• Auto correct shortcuts are gone

• Sort messages by category

• Does not work with on-prem Exchange Server

• Lots of missing Enterprise controls, such as using Group Policy to prevent users from adding their personal accounts.

• Cannot drag-n-drop emails into other Office apps

• Quick Steps cannot create new email

• Cannot import Holidays into Calendar (.hol files)

• Cannot minimize to system tray

• Can’t view headers of attached emails

• Gray theme missing, only white and dark available

• Cannot change icons of quick steps

[via reddit ]