Summary
You can now create and size Exchange Online mailboxes correctly, delegate access without misrepresenting who sent a message, recognize how mail moves into and out of Exchange Online, and provision a Teams workspace with the right channel visibility and Copilot behavior for a sensitive meeting.
What you learned
- Exchange Online mailboxes come in user, shared, and resource types, and a shared mailbox needs an Exchange Online Plan 2 license only after it exceeds 50 GB of free storage, with conversion order (license first, then remove) mattering just as much as the size threshold.
- Full Access lets a delegate open and manage a mailbox but grants no ability to send from it, while Send As hides the delegate's identity and Send on Behalf discloses it, and Send As takes precedence whenever a delegate holds both.
- Exchange Online Protection filters inbound and outbound mail by default through an MX record with no configuration required, and accepted domains and connectors are the settings you'd turn to only when a scenario needs custom routing.
- Creating a team also provisions a Microsoft 365 group with its own mailbox, calendar, SharePoint site, and OneNote notebook, and choosing standard, private, or shared for each channel controls exactly who can see that channel's conversations and files.
- A Teams meeting policy controls Copilot through two independent settings, -AllowTranscription and -Copilot, and getting the combination right—plus confirming the Copilot license and checking for end-to-end encryption—determines whether a meeting gets the recap experience you expect.