A site mailbox can be used from a SharePoint team site to store and organize team email. It can also be used from Outlook 2013 that ships in Office 365 ProPlus for team email, and as a way to quickly store attachments and retrieve documents from the team site.
Before you use site mailboxes at your organization, especially if you plan to use them from Outlook, read this article to understand the requirements and setup considerations. See Frequently asked questions to understand questions users might ask and to troubleshoot access issues.
In this article
When and how to use a site mailbox
To get started, learn how a site mailbox can help a team to collaborate. When you’re ready to set up and use a site mailbox, see the following:
Permissions and requirements
Permission to work with site mailboxes is controlled by adding people to specific groups on the SharePoint site. The following table shows who can do what.
||Who can do it
|Send email to the site mailbox email address.
|Create a site mailbox for the site.
||Anyone in the SharePoint owners group for the site.
|Read, organize, reply to, or delete email from the site mailbox in SharePoint.
- Anyone in the default owners group or the default members group for the site (anyone with Contribute permissions) can use the site mailbox from SharePoint. People can be listed in the owners or members group as individuals or as part of a security group.
|Use a site mailbox from Outlook 2013 that ships in Office 365 ProPlus.
Important Be aware of the following:
- Outlook 2013 that ships in Office 365 ProPlus is required.
- No other version of Outlook allows you to use a site mailbox as described here.
- Outlook 2013 that ships in Office 365 ProPlus is available only in some Office 365 subscription plans.
- The user’s individual user name must be listed in the SharePoint default owners group or the default members group.
- If you add a security group with the user already in it to the SharePoint group, they can’t see the site mailbox in Outlook 2013 that ships in Office 365 ProPlus , even though they can use it from SharePoint.
For hybrid configurations, to see a site mailbox in Outlook 2013 that ships in Office 365 ProPlus, the user must have an Exchange mailbox in Outlook 2013 that ships in Office 365 ProPlus.
|Send email from the site mailbox email address.
||By default, email sent from the site mailbox has a From address of the individual who sends the email. To allow a user to use the site mailbox email address as the From address, you can give the user Send As permission for the site mailbox email address.
Frequently asked questions about managing site mailboxes
Here are answers to common questions that might come up as you start using site mailboxes in your organization.
Using site mailboxes
How can a site member find out who can see the site mailbox?
In Outlook, right-click your account name on the navigation pane, and then click Manage All Site Mailboxes. A new window opens that lists all the site mailboxes you have access to. Double-click the site mailbox, and then click users.
You can also use Outlook Web App. At the top-right corner, click Settings , click Options, click site mailboxes, double-click the site mailbox, and then click users.
Can I copy an email into the site mailbox in Outlook, rather than moving it?
When you drag an email from your mailbox into the site mailbox, the email is moved to the site mailbox. To copy it, right-click the email to drag it into the site mailbox, and then click Copy.
What happens if two people try to upload the same document to the site mailbox by using Outlook?
Each document must have a unique file name. The second user receives an email, stating that the file couldn’t be added because a file with the same name already exists. The email includes the attachment.
What happens if two people simultaneously edit a draft email in the site mailbox by using the SharePoint site’s Site Mailbox app?
The second person’s edits overwrite the first person’s changes.
Working with documents from Outlook
Can a user check out a file from Outlook?
No. To check out a file, you must go to the team site in SharePoint.
If your SharePoint workflow requires checking documents out, the documents can’t be edited from Outlook.
What happens if two people edit the same document from a site mailbox in Outlook?
SharePoint manages the revisions and merges the changes.
How is SharePoint metadata set when a user drags a document or an attachment to the site mailbox?
When a user drags an attachment or a document into a site mailbox in Outlook, data about the attachment or document is saved. The following table shows the Outlook properties that are saved as SharePoint metadata.
|Outlook Property Name
Last modified by
Last modified by
Last modified at
Checked out to
Checked out to
If your document library requires more metadata and a user drags the document into a site by using Outlook, the document shows as checked out in SharePoint until the same person goes to SharePoint and adds the required metadata.
How often is Outlook synchronized with a site mailbox?
When a site mailbox is open in Outlook or in SharePoint, data is synchronized every 15 minutes. Outlook site mailbox information is synchronized each time Outlook is opened.
If a manual sync is needed, any user can start a sync from Outlook or Outlook Web App. In Outlook, right-click your account name on the navigation pane, and then click Manage All Site Mailboxes. A new window opens with a list of all the site mailboxes that you have access to. Double-click the site mailbox, click sync status, and then click start sync. In Outlook Web App, at the top-right corner, click Settings , click Options, and then click site mailboxes. Double-click the site mailbox, click sync status, and then click start sync.
What happens if I drag an attachment or a document that’s in Outlook to the site mailbox, and SharePoint can’t save the document?
If a document can be saved to the SharePoint document library, it’s saved. If it can’t be saved, you’ll get an email that has the document saved as an attachment.
What should I do if I see a Sync Issues folder in my site mailbox?
A Sync Issues folder appears if either a synchronization fails or a document can’t be uploaded or deleted. If you can’t upload or delete a file from Outlook, try using the SharePoint site to upload or delete your file on the SharePoint site. To get to the SharePoint site, from your site mailbox in Outlook, right-click your documents folder, and then click Open in Web Browser.
If a document fails to synchronize from the SharePoint site to the site mailbox in Outlook, try a manual sync to see if that resolves the problem. A manual sync must be done from Outlook Web App for your account, not from SharePoint. In Outlook Web App, click Settings , click Options, and then click site mailboxes. Double-click the site mailbox, click sync status, and then click start sync. If that doesn’t succeed, click email me details, troubleshoot your issue, and contact Support, if needed.
Creating and removing site mailboxes
Do I need to assign a license to the site mailbox email address?
No. The site email address does not require an Exchange license.
Are there situations when I shouldn’t use a site mailbox?
There are times when a site mailbox may not be appropriate:
- Consider confidentiality—any email in a site mailbox can be read or forwarded by any site member.
- Because the site mailbox is a shared workspace, any site mailbox user can rearrange and delete email.
Can I rename a site mailbox?
The display name of a site mailbox is the SharePoint team site display name. If you change the display name of the site in SharePoint, the display name also changes in Outlook. However, the site email address won’t be changed.
Can I change a site mailbox email address?
No. The email address for a site can’t be changed after it’s created. The email address is generated from the display name for the site when the site mailbox was created.
If the site display name uses characters from a non-English alphabet or has three or fewer characters from the English alphabet, the display name isn’t used for the email address. Instead, to ensure that the email address is valid, the email address is automatically generated. Automatically generated email addresses begin with a prefix of SM, followed by the two-digit year, the three-digit day of the year, and four random letters.
Can I add a prefix to site mailbox email addresses for new sites?
You can use the Set-SiteMailboxProvisioningPolicy Exchange Online Windows PowerShell cmdlet with the –AliasPrefix parameter to create a prefix to use with all new site mailboxes.
Can I delete a site mailbox?
Can I automate creation of site mailboxes?
- To create a site mailbox for an existing SharePoint site by using your automated provisioning system, install the Site Mailbox app.
- Using Windows PowerShell with the Exchange Online cmdlets, run the following command to create the site mailbox and set the display name:
New-SiteMailbox –DisplayName “<Site display name>” –SharePointUrl https://domain.sharepoint.com/sites/<site_name>
Here’s an example of how to set up a new site mailbox on the marketing team site:
New-SiteMailbox –DisplayName “Marketing” –SharePointUrl https://contoso.sharepoint.com/sites/marketing
For more information about cmdlets that are used for managing site mailboxes, see Sharing and Collaboration cmdlets.
How do I control the maximum mailbox size?
You can use the Set-SiteMailboxProvisioningPolicy Exchange Online Windows PowerShell cmdlet to control the maximum size of email messages that can be received, when mailbox size warnings are issued, and maximum mailbox size.
Are site mailbox usage statistics available?
Yes. You can use the following Windows PowerShell cmdlets to get usage information:
Get-SiteMailbox: Get basic information about a mailbox.
Get-MailboxFolderStatistics: View the number of items and folder size.
Get-MailboxStatistics: View the last sign in time.
For more information about using these cmdlets, see Sharing and Collaboration cmdlets.
Troubleshooting access to site mailboxes
Why can’t a user see a site mailbox in Outlook even though they can see it in SharePoint?
There are several reasons why a user might be able to see a site mailbox in SharePoint but not in Outlook. Check the following:
- Make sure the user is using a supported version of Outlook.
- Make sure the user has been added to either the site owners group or the site members group as an individual user, rather than as part of a security group.
- Only 10 site mailboxes can be used at one time in Outlook. If a user already has 10 site mailboxes set up and wants to see more of them, the user needs to first hide some site mailboxes. For information about how to clear the Show in Outlook check box, see Access project emails and documents from one place.
Why can a user see a document in SharePoint, but not in the site mailbox in Outlook?
For a document to be visible in the site mailbox in Outlook, the document library that contains the document must be pinned to the site Quick Launch.
Why can a user see a document in a site mailbox in Outlook, but not in SharePoint?
Outlook lists all documents, but SharePoint lists only documents that the user has read permission for. If a user doesn't have read-permission for a specific document, the document’s name is displayed in the site mailbox in Outlook, but the Outlook user can’t open the document.