About working offline

When you use a Microsoft Exchange Server e-mail account (e-mail account: The server name, user name, password, and e-mail address used by Outlook to connect to an e-mail service. You create the e-mail account in Outlook by using information provided by your administrator or Internet service provider (ISP).), working offline allows you to continue working with a local copy of your information. The reasons to work offline are varied, but can include the following:

  • The Exchange server is offline for maintenance.
  • You are traveling and can’t connect to your Exchange server.
  • You find performance unacceptable when using a slow connection to the server, such as dial-up connections with a 56 Kbps modem.

Any time you choose to work offline, Microsoft Outlook only attempts to establish a connection to the Exchange server when you request it or specify to do so in Send/Receive groups.

ShowOffline folders

Offline folders are replicas of the folders found in your mailbox (mailbox: Location on a Microsoft Exchange server where your e-mail is delivered. Your administrator sets up a mailbox for each user. If you designate a personal folder file as your e-mail delivery location, messages are routed to it from your mailbox.) on the Exchange server. These local copies of the server folders are kept on your computer in an Offline Folder file (.ost) (Offline Folder file: The file on your hard disk that contains offline folders. The offline folder file has an .ost extension. You can create it automatically when you set up Outlook or when you first make a folder available offline.) and available even when your network connection is unavailable.

Offline folders make it possible to take a folder from a server location, work with the contents of the folder when you are not connected to the network, and then when connected again, update the folder and its corresponding server folder to make the contents of both identical. This process is called synchronizing folders.

You can add, delete, and modify the contents of an offline folder exactly as you can with a folder on a server. For example, you can change and move items (item: An item is the basic element that holds information in Outlook (similar to a file in other programs). Items include e-mail messages, appointments, contacts, tasks, journal entries, notes, posted items, and documents.) between folders, send messages that are placed in your offline Outbox, and read your offline public folders. Meanwhile, new messages are kept in your Inbox on the server, and other people might add, delete, and change items in public folders. You will not be aware of these changes on the server until you synchronize.

Once an .ost file is created, it needs to be synchronized with the server so that the contents in both files remain identical.

Synchronized information includes:

  • Headers     For e-mail items only, a descriptive identifier that provides the sender's name, subject line of the message, time the message was received, and size of the message.
  • Full items     Includes the header, the body of the message, and any attachments, including embedded objects or pictures.

When you work offline, folders that are synchronized are determined by Send/Receive groups (Send Receive group: E-mail accounts and folders that you can group and set common options for, such as download headers or messages, size limits on downloaded messages, behavior online vs. offline, and time interval for connecting to server.). With Send/Receive groups, you can choose which folders are synchronized and kept current so when a connection to the server isn't possible or you choose to work offline, you can continue to work with those items. You can also specify that updates to the Address Book (Address Book: The collection of address books that you can use to store names, e-mail addresses, fax numbers, and distribution lists. The Address Book may contain a Global Address List, an Outlook Address Book, and a Personal Address Book.) be downloaded.

ShowSend/Receive groups

If you choose to work offline, by default, the Calendar, Contacts, Deleted Items, Inbox, Outbox, Sent Items, and Tasks folders are selected to be synchronized. You can select additional folders, including public folders, or remove any of the default folders in the Send/Receive Settings dialog box under Folder Options.

 Note   Including public folders may significantly increase the size of your .ost file and increase synchronization time.

If you are connecting to Microsoft Exchange Server 2003, for e-mail folders you can specify that only message headers (message header: Summary information that you download to your computer to determine whether to download, copy, or delete the entire message from the server. The header includes these fields: Subject, From, Received, Importance, Attachment, and Size.) are to be downloaded, or you can specify that only headers be downloaded for items (item: An item is the basic element that holds information in Outlook (similar to a file in other programs). Items include e-mail messages, appointments, contacts, tasks, journal entries, notes, posted items, and documents.), including any attachments, that exceed a specified size. This is useful when you want to be able to see all of the items in the folders specified for the Send/Receive group, but want to choose which full items are downloaded.

You can then review the headers, and decide which items you want to fully download during the next synchronization. You can specify that synchronizations occur on a specified schedule, or you can manually initiate a synchronization.

When you are finished making changes, you use a Send/Receive group to connect to your server and send any e-mail messages that you composed while you were offline. If you selected headers for which you want to download the full items, those items are downloaded during the Send/Receive and any changes are synchronized with the Exchange server.

ShowSwitching to and from working offline

When you work offline, there is no connection to your e-mail server. Changes made while you are working offline are synchronized with your Exchange server mailbox (mailbox: Location on a Microsoft Exchange server where your e-mail is delivered. Your administrator sets up a mailbox for each user. If you designate a personal folder file as your e-mail delivery location, messages are routed to it from your mailbox.) when you switch back to online state. There are several ways you can switch to offline state:

ShowRemote Mail

Remote Mail provides a way to synchronize your Inbox only to a local Personal Folders file (.pst) using a dial-up connection. Remote Mail makes it possible for you to exclude the messages you don't want to download by first downloading the message header (message header: Summary information that you download to your computer to determine whether to download, copy, or delete the entire message from the server. The header includes these fields: Subject, From, Received, Importance, Attachment, and Size.) and then deciding which ones you want to download the complete messages for. This way you can screen out messages that are less urgent, which is especially useful when you're away from the office and your connection speed or cost is a concern.

Unless you are using a Microsoft Exchange Server e-mail account and have configured Outlook to deliver and store your information in a Personal File file (.pst) on your computer, it is recommended that you use Offline folders and Send/Receive groups (Send Receive group: E-mail accounts and folders that you can group and set common options for, such as download headers or messages, size limits on downloaded messages, behavior online vs. offline, and time interval for connecting to server.).

 Note   Outlook includes the ability to download and process Inbox headers for Internet mail accounts, such as POP3 (POP3: A common protocol that is used to retrieve e-mail messages from an Internet e-mail server.) accounts, but the Remote Mail feature is exclusive to Exchange accounts.

ShowCached Exchange Mode and working offline

If you use an Exchange server e-mail account, it is recommended that you use Cached Exchange Mode. Most of the reasons to work offline are eliminated when you use Cached Exchange Mode. The lack of a network connection is virtually transparent to you because you can continue to work with your items (item: An item is the basic element that holds information in Outlook (similar to a file in other programs). Items include e-mail messages, appointments, contacts, tasks, journal entries, notes, posted items, and documents.).

By default, Cached Exchange Mode creates and uses an Offline Folder file (.ost) (Offline Folder file: The file on your hard disk that contains offline folders. The offline folder file has an .ost extension. You can create it automatically when you set up Outlook or when you first make a folder available offline.) automatically, and then downloads and maintains a synchronized copy of the items in all folders in your mailbox (mailbox: Location on a Microsoft Exchange server where your e-mail is delivered. Your administrator sets up a mailbox for each user. If you designate a personal folder file as your e-mail delivery location, messages are routed to it from your mailbox.). You work with your information on your computer and Outlook synchronizes it with the server.

Whether you are at the office, at home, or on an airplane, network changes or availability are transparent to you. When your connection to the Exchange server is interrupted, you can continue to work with your data. When a connection is restored, Outlook automatically synchronizes changes and the folders and items on the server and on your computer are once again identical. Managing your connection to the server and keeping your data up-to-date is handled by Outlook. There is no need to switch to working offline and no need to keep trying to reconnect to the server — it is all automatic.

Cached Exchange Mode also frees you from having to set up Send/Receive groups (Send Receive group: E-mail accounts and folders that you can group and set common options for, such as download headers or messages, size limits on downloaded messages, behavior online vs. offline, and time interval for connecting to server.), picking folders you want available offline, and keeping those folders synchronized. That’s all handled by Outlook.

The only time when you might still choose to work offline is when you want greater control over what is downloaded to your local copy of your Exchange mailbox. This could include situations where you are using a connection device or service that charges based upon the amount of data your transfer. Cached Exchange Mode keeps everything up-to-date. Working offline allows you to use Send/Receive groups to refine the type and amount of information that is synchronized.

 
 
Applies to:
Outlook 2003