About configuring e-mail-enabled document libraries

Microsoft Windows SharePoint Services includes the ability to link a document library with a public folder based on Microsoft Exchange 2000 or later. Any documents attached to messages in the public folder can be automatically inserted into the document library; the document library then displays the document, plus the from address, the subject line, and the date and time that the attachment was inserted into the document library. Note that the body text of the e-mail message is not preserved. It remains in the public folder but is not transferred to the document library.

A user can simply send e-mail to the public folder, with an attached document, and the document will be automatically added to the correct document library on a SharePoint site. For example, if you are using an XML template to store invoice information, a user could fill out the XML invoice and e-mail it to the public folder. The XML file is then posted to the document library and would be available for rolling up into larger reports on invoices, or for easy retrieval.

About e-mail and document library security

Because this feature relies on e-mail to transport documents, it uses the same security rules as all e-mail messages. Before enabling this feature, you should be aware of the following issues and vulnerabilities:

• Because e-mail messages can cross firewalls, external users can use this method to send documents to an internal SharePoint site. This is useful for many scenarios, such as sending expense reports in from the field, but it can also open your site to unwanted junk e-mail messages, or spam. For information about controlling spam in public folders, see the Exchange 2000 Server documentation.
• Because e-mail messages can carry documents with viruses, you might end up with a virus-laden document on your site. However, documents inserted into a document library from e-mail attachments can be scanned for viruses like any other documents in document libraries. For more information about virus scanning in Windows SharePoint Services, see About virus protection.
• Because e-mail addresses can be spoofed, the from address is preserved in the document properties and displayed in the document library. Trust the from address as much or as little as you trust other e-mail addresses.
• To allow this feature to work, the document libraries allow anonymous insertions from e-mail attachments. You cannot control who has rights to add attached documents to this document library. However, you can control who can add documents directly to the document library, and you can control who has rights to post to the public folder by using the Exchange Server user management tools.
• As with any public folder or document library, there is the possibility that a malicious user could add so many documents that the site or server's storage capacity is filled, thus blocking other users from accessing the site or server. Be sure to control the list of users with access to the public folder, and consider using quotas to control the size of the site. For more information about quotas, see About quotas and locks.

This feature adheres to the blocked file extension rules for a document library. Any documents with file extensions that are blocked at the server level are also blocked from being added to an e-mail-enabled document library. For example, if you have a file with an .exe file extension, and you send it to the public folder, it will not be transferred to the document library. For more information about blocked file types, see Configure blocked file types.

How it works

The Microsoft SharePoint Timer service controls when the public folder is checked for new attached documents. When the Timer service event runs, the service checks the public folder for new documents and inserts them into the document library. The SharePoint Timer service simply inserts documents; it does not update, overwrite, or delete documents. If the same document is added to the public folder more than once, that document will appear more than once in the document library. However, each document in the document library will have a unique file name (which is automatically generated by adding numbers, such as "1" to the end of the file name, so that filename.doc when added again becomes filename1.doc).

You can use this feature with any document library, or any list based on a document library template such as a custom document library, except picture library, which is not supported. The data sent to the document library along with the document is fixed. Any additional fields (even required fields) that you specify in the document library properties are ignored when documents are inserted.

Managing the public folder

You must configure the Exchange Server public folder to work with Windows SharePoint Services before you can enable this feature. After you configure the feature, you must continue to perform the public folder administration tasks from within Exchange.

To use this feature, you must use the Exchange 2000 Server administration tools to do the following:

• Create the public folder.
• Grant read access to the appropriate Windows SharePoint Services application pool accounts. If you are using one account for all virtual servers, grant that account access. If you are using separate accounts for each virtual server, you must grant the virtual server accounts access to the appropriate public folders.

  If you prefer not to grant access to the application pool accounts, you can instead give the anonymous user account access to read the public folder. This is a less secure method than granting access to the application pool account.

• Determine which e-mail distribution list to allow to post to the public folder, and grant the distribution list appropriate access to the public folder. Note that you will need to enable the public folder to receive e-mail. This is not turned on by default, so the Exchange 2000 Server administrator will need to create an e-mail address for the public folder.
• Continue to manage the public folder and the access to the public folder.

For more information about managing public folders and managing user access in Exchange 2000, see the Exchange 2000 Server documentation.

Enabling e-mail access to document libraries

To enable this feature, you must be a local server administrator or a member of the SharePoint Administrators group. You enable this feature by entering an Exchange server name in the Virtual Server General Settings page. After you have enabled this feature for a virtual server, any administrator of a site on that virtual server can enable the feature for a document library in his or her site.

Related Topics

Configure e-mail-enabled document libraries

About virus protection

About quotas and locks

Configure blocked file types