PIM Manager settings · Settings > Mail & alerting

Shared mailbox: name, domain and display name

Key	Mail.SharedMailbox
Where	Settings > Mail & alerting > Mail sending (also Get Started > Mail sender)
Type	Text
Default	PIM-Engine at the tenant's initial domain, display name 'PIM Manager'

What it does

The Exchange Online shared mailbox PIM Manager sends as when the mail mode is Shared mailbox -- named by your organisation: the mailbox name, one of the tenant's verified domains and the display name (step 1 of Get Started > Mail sender). The setup command is built from these values (-MailboxName, -MailDomain, -DisplayName). Step 2, Check and send a test mail, makes that mailbox the sender. Every mail is sent from this address through Microsoft Graph.

When set

When set: the PIM Manager sends from this mailbox immediately; the engine and scheduled jobs use it from their next run. A changed address makes the earlier test-mail proof stale, so Get Started shows the step as not done until a new test mail succeeds.

When blank or default

When blank: in Shared mailbox mode nothing is sent -- mails are rendered only, TAP delivery is refused as 'no sender configured', and alerts show 'configure to enable'.

Risk and how to reverse it

If the identity may not send as this mailbox (the setup script was not run for it), every send fails with a permission error -- the Mail check and the test mail show it. Clearing the field in the form does not clear the stored address; enter another address instead. Reversible at any time.

Requires

Admin role in PIM Manager. Mail mode Shared mailbox. The setup script (run once by an Exchange or Global Administrator, browser sign-in) must have scoped Mail.Send for the PIM Manager and engine identities to exactly this mailbox. A shared mailbox needs no licence once the tenant has an Exchange Online plan.