How can we help?
Why aren’t emails I send from a shared mailbox showing up in my own Sent Items? (Outlook)
Do your agents send email from a shared mailbox in Outlook, only to find those messages never land in their own Sent Items folder? The email goes out fine and the recipient gets it, but as far as the sender’s Sent Items is concerned, it never happened.
This is almost never a bug. It is a setting — and there are only two likely culprits. This article shows you how to identify which one you have and how to fix it.
Why this matters more than it looks
A missing sent email is annoying. But if you use EmailAnalytics to report on a shared inbox, it is also the thing that quietly breaks your per-agent numbers.
Here is why. When an agent sends from a shared mailbox, two copies of that message are supposed to be saved:
- One in the shared mailbox’s Sent Items — so the whole team can see what went out.
- One in the agent’s own Sent Items — and this is the copy that identifies who sent it.
That second copy is how individual agent activity gets attributed. Without it, the message still exists in the shared mailbox, but there is no longer anything connecting it to the person who wrote it.
Both of the causes below break the agent’s copy while leaving the shared mailbox’s copy perfectly intact. That is what makes this worth checking proactively: the shared inbox looks completely normal, nobody reports a problem, and the only symptom is that one or more agents show far less activity than they are actually doing.
If an agent’s numbers look impossibly low, this is the first thing to check.
What is supposed to happen
Three conditions have to be true at the same time for both copies to be saved:
- The shared mailbox was added to Outlook as a shared mailbox, not as a separate email account.
- No setting on the agent’s computer is redirecting their copy away.
- The shared mailbox is set to keep copies of sent mail (a setting your Microsoft 365 admin controls).
Condition 3 is the one most admins already know about, and it is not the one that causes this problem. Conditions 1 and 2 are the two causes in this article, and they are the ones that break agent attribution.
Step 1: The two-minute test (anyone can do this)
You do not need admin access or technical knowledge for this part. It tells you whether the problem is on the computer or on the server, which decides everything that follows.
1. Send a test email from Outlook on the desktop
Open Outlook, start a new message, and set the From field to the shared mailbox. Send it to yourself.
2. Check both Sent Items folders
In the folder list on the left, you will see your own mailbox and the shared mailbox, each with its own Sent Items. Check both. They look identical, so make sure you know which one you are in.
3. Send a second test from Outlook on the web
Go to outlook.office.com, sign in, and send the same kind of test message from the shared mailbox. Check both Sent Items folders there too.
4. Match your result to the table
| What you saw | What it means |
|---|---|
| Missing from your own Sent Items on the desktop, but present on the web | The cause is on that computer. This is one of the two causes in this article — continue to Step 2. |
| Missing from your own Sent Items in both places | Unusual. Skip to the Troubleshooting section at the bottom. |
| Present in your own Sent Items, missing from the shared mailbox’s | A different setting entirely — see How do I get sent items to display in my Outlook shared mailbox? |
| Present in both places | Nothing is broken. You were most likely looking in the wrong Sent Items folder. |
Step 2: Check how the shared mailbox was added (also no admin needed)
This is the most likely cause, and looking it up is read-only — you are not changing anything, so it is safe to check yourself before involving anyone.
There are two ways to put a shared mailbox in Outlook. One of them makes Outlook treat it as its own separate email account, with its own Sent Items folder. That is the setup that breaks things.
| Your Outlook | Where to look |
|---|---|
| Classic Outlook (Windows) | File → Account Settings → Account Settings → Email tab |
| New Outlook (Windows) | Settings → Accounts → Email accounts |
| Outlook for Mac | Outlook → Settings → Accounts |
You are looking at the list of email accounts. Then:
- The shared mailbox is listed there as its own account → this is your cause. It needs to be removed and re-added the other way.
- Only your own email address is listed → this is not your cause. The problem is the registry setting covered in the administrator section.
Can you fix it yourself?
Removing and re-adding the mailbox does not require admin rights — it is a change to your own Outlook setup. But think before you do it unsupervised, for two reasons.
First, the account list includes your own mailbox alongside the shared one, and removing the wrong row is an easy mistake to make in a hurry. Second, if the shared mailbox does not come back automatically after you remove it, you will be locked out of it until someone with Microsoft 365 admin access restores your access — which is a bad surprise in the middle of a shift.
A safe check before you touch anything: go to outlook.office.com and confirm you can open the shared mailbox there. If you can, your permissions are intact, and the worst case is that you work from the web browser until the mailbox is added back in your desktop Outlook.
Our recommendation: do the checks in Steps 1 and 2 yourself, then hand the fix to IT. The diagnosis is the slow part and you have just done it. If you are comfortable and you have confirmed web access, the removal steps are in the administrator section below — do it at the start of a day rather than mid-shift, and stop and ask for help if the mailbox does not reappear.
Sending this to IT
Copy the block below, fill in what you found, and send it to whoever supports your email:
Emails I send from our shared mailbox are not being saved in my own Sent Items folder, only in the shared mailbox’s. This breaks our per-agent email reporting.
I checked Outlook’s account list: the shared mailbox [is / is not] listed there as a separate account.
If it is listed, it needs to be removed and re-added as a shared mailbox instead. If it is not, please check whether DelegateSentItemsStyle is set on my computer. Full steps are here: [link to this article]
For IT administrators
The rest of this article assumes admin access to the affected computer and to Exchange Online PowerShell or the Microsoft 365 admin center.
The target configuration
Verify all three. Getting one right and the others wrong still loses a copy. Work through them in this order — requirement 1 is by far the most common cause, and it is the only one that applies to every Outlook client.
| # | Requirement | Where it lives | If wrong |
|---|---|---|---|
| 1 | Shared mailbox added as automapped or additional mailbox, not as a separate account | Each agent’s Outlook profile | No copy in the agent’s Sent Items — attribution lost |
| 2 | DelegateSentItemsStyle absent or 0, and not pushed by policy |
Each agent’s computer (classic Outlook for Windows only) | No copy in the agent’s Sent Items — attribution lost |
| 3 | MessageCopyForSentAsEnabled and MessageCopyForSendOnBehalfEnabled both $true |
Shared mailbox, server-side | No copy in the shared mailbox’s Sent Items (does not affect attribution) |
Cause A: shared mailbox added as a separate account — diagnosis
Start here. The check itself is in Step 2 above and needs no admin rights — if the agent has already done it, use their answer.
The reason it matters is that the two setup methods change which mailbox Outlook treats as the sending account.
Added as a separate account, the shared mailbox has its own store and its own connection. Selecting it in the From field is not a delegate send — Outlook sends through that account and files the copy in that account’s Sent Items. The agent’s own mailbox is never involved, which is why the copy never appears there.
Added as automapped or as an additional mailbox, there is only one sending account: the agent’s. The shared mailbox is a second set of folders on their existing connection, the send is a true Send As, and the copy lands in their Sent Items.
A correctly configured profile shows only the agent’s own mailbox in the account list. The shared mailbox appears in the folder tree but not as an account — in classic Outlook you can confirm it under Change → More Settings → Advanced → “Open these additional mailboxes,” or it is automapped and appears in neither place.
Cause A: remediation
There is no supported setting that changes this behavior while the mailbox remains a full account. It has to be removed and re-added.
1. Remove the account. Take care to select the shared mailbox and not the agent’s own.
- Classic Outlook (Windows): File → Account Settings → Account Settings → Email tab → select the shared mailbox → Remove
- New Outlook (Windows): Settings → Accounts → Email accounts → Manage next to the shared mailbox → Remove
- Outlook for Mac: Outlook → Settings → Accounts → select the shared mailbox → minus (–) button
2. Close Outlook completely and confirm the mailbox is gone from the folder tree before continuing.
3a. Re-add via automapping (preferred). Confirm the Full Access grant has automapping enabled; if it was granted with -AutoMapping:$false, re-grant it:
Remove-MailboxPermission -Identity shared@contoso.com -User agent@contoso.com -AccessRights FullAccess -Confirm:$false
Add-MailboxPermission -Identity shared@contoso.com -User agent@contoso.com -AccessRights FullAccess -AutoMapping:$trueAllow time to propagate, then restart Outlook and the mailbox reappears on its own.
3b. Or add it manually. Use this if automapping is deliberately off, or you do not want to wait for it to propagate.
- Classic Outlook (Windows): File → Account Settings → Account Settings → Email tab → select the agent’s own account → Change → More Settings → Advanced → Add → type the shared mailbox name → OK → Next → Finish
- New Outlook (Windows): right-click Shared With Me in the folder list → Add shared folder or mailbox → type the shared mailbox name → Add
- Outlook for Mac: Outlook → Settings → Accounts → select the agent’s own account → Delegation and Sharing → Shared With Me tab → + → search for the mailbox → Add
Before you do this, three warnings:
- The local cache is discarded. Nothing is lost server-side, but a large mailbox takes time to resync. Warn the agent that folders may look empty at first.
- Do not end up with two instances. If automapping brings the mailbox back on its own, do not also add it manually.
- Find out why it was set up that way. The one legitimate reason is calendar reminders — Outlook only fires event reminders for a shared mailbox added as a full account. If the team relies on that, you are choosing between reminders and per-agent attribution. Decide deliberately rather than discovering it after the change.
Cause B: DelegateSentItemsStyle — diagnosis
If the profile checks out, look here next. This registry value redirects the sent copy to the shared mailbox instead of the sender’s mailbox. It is often a deliberate change made years earlier to solve the opposite complaint, and it destroys per-agent attribution as a side effect.
Applies to classic Outlook for Windows only. New Outlook, Outlook on the web, Mac, and mobile ignore it — if the affected agent uses one of those and Cause A did not apply, go to the Troubleshooting section.
Note that this value has no effect when the mailbox is set up as a separate account, because in that mode there is no delegate send to redirect. If you found Cause A, fix that first and retest before investigating here.
Run these in a Command Prompt in the affected user’s own session. Do not run elevated or as a different user — HKCU resolves to whoever is running the command, so an elevated prompt reads the admin’s hive and returns a false clean result:
reg query "HKCU\Software\Microsoft\Office\16.0\Outlook\Preferences" /v DelegateSentItemsStyle
reg query "HKCU\Software\Policies\Microsoft\Office\16.0\Outlook\Preferences" /v DelegateSentItemsStyle| Result | Meaning |
|---|---|
| “The system was unable to find the specified registry value” on both | Not set. Not your cause — go to Troubleshooting. |
0x1 under the first path |
Set locally. This is your cause. |
0x1 under the Policies path |
Pushed by Group Policy or Intune. This is your cause, and editing the registry will not hold. |
0x0 |
Explicitly disabled. Not your cause. |
Prefer a GUI? Press the Windows key, type registry editor, press Enter (again: not as administrator), and paste each path into the address bar at the top of the window.
Cause B: remediation
If set locally, clear it and restart Outlook fully:
reg add "HKCU\Software\Microsoft\Office\16.0\Outlook\Preferences" /v DelegateSentItemsStyle /t REG_DWORD /d 0 /fIf pushed by policy, do not edit the registry — it will be reapplied at the next refresh and return as a new ticket. The setting is the Outlook policy “Saving messages sent from a shared mailbox to the Sent Items folder,” under User Configuration → Administrative Templates → Microsoft Outlook → Preferences. In Intune, look under Devices → Configuration profiles. Set it to Disabled or Not Configured, or scope the affected users out, then gpupdate /force and restart.
If the policy is hard to find by name, identify it by the registry location it writes to: software\policies\microsoft\office\16.0\outlook\preferences.
Because requirement 3 below puts a copy in the shared mailbox server-side, turning this off does not cost the team their shared record. You end up with both copies, which is the goal.
Requirement 3: the server-side copy setting
This one does not affect agent attribution, but it is what keeps the team’s shared record intact once Causes A and B are fixed. Check it in Exchange Online PowerShell:
Get-Mailbox shared@contoso.com | Format-List MessageCopyForSentAsEnabled,MessageCopyForSendOnBehalfEnabledIf either is False, set both. Enable both regardless of which permission you think agents hold — the two parameters govern Send As and Send on Behalf separately, and a mailbox with mixed permissions will otherwise behave inconsistently from person to person:
Set-Mailbox shared@contoso.com -MessageCopyForSentAsEnabled $true -MessageCopyForSendOnBehalfEnabled $trueAllow up to an hour to propagate. The change affects new mail only; existing sent items do not move.
Verify the fix
Have the agent send one test message from the shared mailbox, then confirm a copy exists in both their own Sent Items and the shared mailbox’s Sent Items. One copy in only one place means one of the three requirements is still unmet.
Known limitation: Outlook on iOS
Messages sent from a shared mailbox in Outlook for iOS are saved to the shared mailbox’s Sent Items only, never the sender’s. There is no setting that changes this, and no configuration in this article works around it.
The practical consequence: agents who work substantially from their phones will show lower activity than they are actually doing, even on a perfectly configured tenant. If a client’s numbers look low and their configuration checks out, ask how much of the team works from mobile. Outlook on the web is the workaround where the metrics matter.
Advanced: attribution without the agent’s Sent Items
Two options exist for organizations that cannot meet the target configuration everywhere.
Send on Behalf preserves the sender in the message. With Send on Behalf, the message’s from is the shared mailbox but its sender is the actual agent — Microsoft Graph defines sender as the account used to generate the message, distinct from from in delegation scenarios. With Send As, both are the shared mailbox and the individual is unrecoverable from the message. Standardizing on Send on Behalf makes attribution readable from the shared mailbox alone. The tradeoff is that recipients see “Agent X on behalf of Support,” which many organizations reject. Note also that Send As takes precedence when an agent holds both permissions, so Send As has to be removed for this to take effect.
The unified audit log records both. Mailbox auditing is on by default, and SendAs and SendOnBehalf are both logged by default for delegate access on shared mailboxes, capturing the actual sending user, the mailbox sent as, the subject and the timestamp:
Search-UnifiedAuditLog -StartDate (Get-Date).AddDays(-7) -EndDate (Get-Date) -Operations SendAs,SendOnBehalf -ResultSize 1000Useful for spot-checking who actually sent what. Retention depends on licence tier and your Purview audit retention policy, and search results can lag, so treat it as a verification tool rather than a reporting feed.
Troubleshooting
What if neither cause applies?
Confirm “Save copies of messages in the Sent Items folder” is ticked under File → Options → Mail. After that, look at add-ins intercepting sends (CRM connectors most often — test in Outlook safe mode) and retention policies moving items out of Sent Items.
Why does the shared mailbox look fine when agent copies are missing?
Because the two copies are produced by different mechanisms. The shared mailbox’s copy is created server-side and is unaffected by either cause. This is exactly why the problem goes unnoticed — the visible folder is the one that still works.
Why is one agent affected and not the others?
Both causes are per-computer and per-profile. A badly added mailbox or a registry value on one machine affects only that person, which is why partial, uneven reporting is the typical symptom rather than a total blackout.
What if we now get two copies in the shared mailbox?
The registry setting and the server-side setting are both active. Remove the registry setting. The server-side setting is the one to keep — it works identically across every client instead of only classic Outlook for Windows.
Does the permission type change any of this?
Not for the agent’s own copy, which is saved either way. It matters only for the shared mailbox’s copy, which is why both MessageCopy parameters should be enabled rather than just the one you expect to need.
Do we have to restart Outlook?
Yes, fully, after every change. A large share of “the fix didn’t work” reports are Outlook never having been closed.
Helpful links for Outlook shared mailbox setup and usage
- How do I get sent items to display in my Outlook shared mailbox?
- How do I track individual team member activity in a shared inbox / mailbox? (Outlook)
- Microsoft: Add a shared mailbox as an additional account in Outlook desktop
- Microsoft: Messages sent from a shared mailbox aren’t saved to the Sent Items folder
- Microsoft: Email remains in the Outbox when you use DelegateSentItemsStyle
- Microsoft: Manage mailbox auditing