How do I track a shared mailbox or distribution list?

How you set this up depends on how your team replies to emails that come into the shared mailbox or distribution list.

Which setup do you have?

Setup	How your team replies	Where the reply is saved
1. Send on behalf of	From their own mailbox. The reply says Agent name on behalf of Shared mailbox name.	The agent’s own Sent Items
2. Reply as the shared mailbox	As the shared mailbox itself. The reply is from Shared mailbox name.	The shared mailbox’s Sent Items
3. Distribution list	Each agent gets their own copy of the email and replies from their own mailbox. Emails that are auto-forwarded to agents work the same way.	The agent’s own Sent Items

Some teams do both: they reply as the shared mailbox and from their own mailbox. If so, connect the shared mailbox as well as each agent’s mailbox.

Setup 1: Your team uses send on behalf of

This shows how each agent performs on the shared mailbox’s emails.

1. Turn on send on behalf of

Send on behalf of is a permission set up on your mail server, so the reply shows which agent sent it. To set it up for a Microsoft 365 shared mailbox:

Connect to Exchange Online PowerShell.

Run this for each agent, replacing the two email addresses:

Set-Mailbox -Identity shared@yourcompany.com -GrantSendOnBehalfTo @{Add="agent@yourcompany.com"}

For more detail, see Microsoft’s guide: Manage permissions for recipients.

2. Connect the shared mailbox and every agent

Connect both:

The shared mailbox. See How do I add a Microsoft 365 shared mailbox without a password?
Every agent who replies on its behalf.

3. Link the agents to the shared mailbox

Click Entities in the bottom-left corner and go to Shared/group mailboxes.
Click Set up a new shared/group mailbox.
Enter the shared mailbox’s Name and Email, then click Next.
Under Members, search for each agent and click Add.

If your account already uses bulk add, the page asks you to search Microsoft 365 instead of entering a name and email.

Search for the shared mailbox and select it.
Search for each agent and select them. Selecting an agent links them. This screen has no Next or Add button.

To change the agents later, click the ⋮ menu on its row and select Edit.

When you filter reports by this shared/group mailbox, you’ll only see the agents’ work on the shared mailbox’s emails, not their other emails.

Setup 2: Your team replies as the shared mailbox

Connect the shared mailbox as a mailbox. timetoreply reports on the shared mailbox as a whole, but can’t show which agent replied.

If agents reply with Send As from their own mailboxes, also connect each agent. Otherwise their replies are only saved in their own Sent Items, and timetoreply misses them. Or ask a Microsoft 365 admin to save a copy in the shared mailbox (see the note above).

If you don’t have the shared mailbox’s password, see How do I add a Microsoft 365 shared mailbox without a password?

Setup 3: Distribution list

Connect every agent on the distribution list. If emails reach the list by being forwarded from another mailbox, add that mailbox as an alias.

What timetoreply needs

For any of these setups to track correctly:

The email that came in: the mailbox it first arrived in must be connected.
The reply: the mailbox it was sent from must be connected.
Everyone involved: every mailbox that’s part of the shared mailbox or distribution list must be connected, for the full picture.
Auto-forwarded emails: if emails reach the shared mailbox or distribution list by being forwarded from another mailbox, add that mailbox as an alias, so timetoreply knows the emails belong together.
Don’t delete too soon: keep emails for at least 30 days.
Moved or archived emails (Exchange only): tell us which other folders emails are moved to, so we can see them. This isn’t needed for Microsoft 365 or Google Workspace.

Shared mailboxes and distribution lists: the difference

	Shared mailbox	Distribution list
Copies of each email	One copy, in the shared mailbox’s Inbox. Anyone with access can read it.	Each member gets their own copy.
Who replies are from	Members with Send As permission can send from the shared mailbox’s address.	Usually the member’s own address. An admin can give members Send As or Send on behalf permission for the list.
Deleting an email	Deletes it for everyone.	Only deletes the member’s own copy.
Seeing replies	Members can see replies sent from the shared mailbox.	Members only see each other’s replies if the list is copied in.