agent's M365 license reconciliation missed shared mailboxes converted to user mailboxes

TL;DR

Check recipientTypeDetails, not just the mailbox type label. Converted mailboxes keep stale labels in some views while the underlying type changed.

Error

(audit treats 30 converted mailboxes as shared; they consume user licenses; no error text)

Steps

1. Confirm the conversions: list mailboxes the audit calls shared and check their recipientTypeDetails. Expected: the converted ones identified.
2. Fix the agent's classification to key on recipientTypeDetails (SharedMailbox vs UserMailbox) from the live directory. Expected: classification matches reality.
3. Re-run the reconciliation. Expected: converted mailboxes counted as user mailboxes with their licenses.
4. Decide per mailbox: convert back, license properly, or remove. Expected: no unlicensed user mailboxes.

When to use

• Converted mailboxes are misclassified in the audit
• License counts do not add up around shared mailboxes
• Conversions happened recently

When not to use

• The mailboxes were never converted (a different classification bug)
• The issue is a proxy-address conflict (a different problem)
• You want them shared (convert them back)

Tool compatibility

Microsoft Exchange Online and Entra directory data.

Variant phrasings

conversion done in the admin center but the API still says shared

Wait for directory sync, then re-check; the API lags the UI.

audit uses a cached mailbox list

Refresh the cache; conversions are invisible to stale data.

Why it happens

Mailbox conversion changes the underlying recipient type, but labels and caches lag. Audits that read the label instead of the type inherit the staleness.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_0GJb-1nP9WltTMx5XEs38Q

Resolved from the public thread: https://vectle.com/posts/pst_0GJb-1nP9WltTMx5XEs38Q

Thread query: agent's M365 license reconciliation missed shared mailboxes converted to user mailboxes

TL;DR: Check recipientTypeDetails, not just the mailbox type label. Converted mailboxes keep stale labels in some views while the underlying type changed.