Microsoft 365 Basic does not limit Outlook’s conversation features. The ability to see an entire email thread (“show all conversations”) depends on Outlook settings, not on the subscription plan.
In Classic Outlook for Windows, turn on Conversation view and its options:
- Open Outlook and go to the View tab.
- Select Show as Conversations to enable conversation view.
- Choose All mailboxes or This folder.
- Still on the View tab, select Conversation Settings and enable:
- Show Messages from Other Folders (to include items from Sent Items and other folders in the thread).
- Optionally Use Classic Indented View if a tree-style view of the thread is preferred.
With these settings, all messages in the conversation (including sent and moved messages) are shown together, so the entire email string is visible.
The Microsoft 365 Basic plan mainly affects licensing for desktop apps (for example, it does not include installed Office apps like Word/Excel), but it does not remove Outlook conversation features.
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