Contoso Legal LLP
3 lists need a look. Mail to an empty list reaches nobody, a list without an owner (or owned only by people whose sign-in is blocked) has nobody keeping its members right, and a big list anyone outside can mail is a phishing target. Give each list an owner who still works here, and delete lists nobody uses (Exchange admin centre, Recipients > Groups > Distribution list). To stop outside mail, open the list's Settings and untick "Allow people outside of my organisation to send to this group".
| Why | Members | Owners | Last mail received |
|---|---|---|---|
| No owner, No mail in 90 days medium | 9 | None | 25 May 2026 |
| No members, No owner, No mail in 90 days medium | 0 | None | 7 Sep 2025 |
| Only leavers own it medium | 6 | bobby.marsh@contoso.example | 12 Oct 2026 |
7 distribution lists. Lists that accept mail from outside can be mailed by anyone on the internet; most lists only need mail from colleagues.
| List | Address | Members | Owners | External members | Accepts mail from outside | Mail in the last 30 days |
|---|---|---|---|---|---|---|
| Christmas party 2023 medium | xmas2023@contoso.example | 9 | None | 0 | No | 0 |
| Old projects medium | oldprojects@contoso.example | 0 | None | 0 | No | 0 |
| Sales team medium | salesteam@contoso.example | 6 | bobby.marsh@contoso.example | 0 | No | 43 |
Each list's direct members (the first 200 of a big list). A member that is itself a list passes mail on to its own members.
Data from Distribution lists (), Mailboxes (), Users ().