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Send email through a shared mailbox in Outlook Web App
Log in to Outlook Web App.
Click the settings gear icon in the upper-right corner.
Click View All Outlook Settings.
On the left side of the screen, under the Mail section click Compose and Reply.
Under Message Format, place a check by "Always show From," and click Save, then close.
Click + New Message.
Click From and start typing the name of the account for which you have "Send As" permission. When it appears, click to select it.
Send a test message to an address of your choosing to complete this one-time process.
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