Chapter 3 - Interoperability
  
As an administrator, you need to know how the Microsoft® Outlook™98 works together with other workgroup clients in your organization. Read this chapter to find out how Outlook interoperability with other Microsoft messaging, calendar and group scheduling, and project management products takes the administrative trouble out of upgrading or managing a mixed client environment.
Introduction
  
Microsoft Outlook provides interoperability with other Microsoft and third-party messaging and collaboration products, which makes it easy for administrators to manage mixed clients. Outlook, like Microsoft Exchange Client, can use either Microsoft Exchange Server or Microsoft Mail 3.x as its messaging transport. In addition, Outlook can use Internet messaging protocols, including POP3/SMTP and IMAP4. A high level of interoperability enables users of different Microsoft messaging and collaboration clients on different platforms to send and receive mail, as well as to perform group scheduling activities. 
In a mixed-client environment, users who continue to use previous Microsoft messaging and group scheduling clients cannot take full advantage of Outlook's enhanced user interface and capabilities. These interoperability differences are similar to the differences users notice when they upgrade other applications (such as upgrading from Microsoft Word 95 to Word 97). For example, non-Outlook users may not be able to gain access to or view an Outlook user's messages or other Outlook information in the same way that another Outlook user would. 
For organizations that are managing both Outlook 97 and Outlook 98 environments, there are very few significant interoperability issues between these two versions. Because the versions are built with the same file format, there is complete interoperability for group scheduling activities (sending and receiving meeting requests, viewing free/busy times or details, and delegating access). Outlook 97 and Outlook 98 users can also send and receive mail across versions. The only significant interoperability issues are new Outlook 98 features, such as HTML mail, Stationery, vCard, vCalendar, and iCalendar—which are not supported in Outlook 97 (with the exception of vCard, which is available as a free add-on to Outlook 97).  
Interoperability with MS Exchange Client
  
In an environment where Outlook users must share information with Microsoft Exchange Client users, all users can exchange e-mail with each other. However, because many Outlook capabilities go beyond those of Microsoft Exchange Client, Outlook users should be aware that their co-workers who are using Microsoft Exchange Client might not be able to view or use portions of the Outlook users' messaging information the same way as another Outlook user would. 
Exchanging Messages
  
In a mixed environment, Outlook users should be aware that their co-workers who use Microsoft Exchange Client cannot take full advantage of many Outlook messaging features, including the following:
·	Enhanced standard message form. Microsoft Exchange Client users who view messages created in Outlook see the messages in the Microsoft Exchange Client standard message form; this form does not support the advanced features of the Outlook standard message form, such as message expiration. As a result, some of the information in the Outlook message may not be viewable to Microsoft Exchange Client users.
·	Extended message properties. When a Microsoft Exchange Client user opens an Outlook message, extended Outlook message properties, such as voting buttons, are ignored because they are not recognized by Microsoft Exchange Client. This means that some messages created in Outlook may appear different to Microsoft Exchange Client users. However, Outlook recognizes all Microsoft Exchange Client message properties. 
·	Private items. When an Outlook user marks an item (such as an e-mail or calendar item) as "Private," other Outlook users cannot view the item. However, Microsoft Exchange Client users can view the item if they have been granted folder access privileges for the folder where the item is stored. Because Outlook folder-level privacy is absolute, the Outlook workaround for this functionality difference is to have Outlook users put private items in a separate folder, which they do not share or for which they have set restrictions.
·	Non-table views. Microsoft Exchange Client users can display Outlook table views—views that consist only of rows and columns—if the Convert to Exchange views check box is selected as part of folder properties for the Outlook folder. However, Microsoft Exchange Client cannot display Outlook non-table views (such as the day, week, and month views in the calendar) and card, icon, and timeline views. When Outlook and Microsoft Exchange Client users access the same set of public folders, Microsoft Exchange Client users cannot display any non-table views created by Outlook users.
·	Saved views. Outlook and Microsoft Exchange Client use different formats to create saved views. Outlook recognizes both formats, so Outlook users can use any Microsoft Exchange Client view, as well as all Outlook views. In contrast, Microsoft Exchange Client does not recognize the Outlook format, so Microsoft Exchange Client cannot use Outlook views by default. 
	Outlook users can choose to maintain two copies of all saved table views in a folder automatically—one copy in Outlook format and one copy in Microsoft Exchange Client format. This workaround enables Microsoft Exchange Client users to use Outlook forms, although any Outlook-specific view features, such as formula fields, are not included in the Microsoft Exchange Client copy. Also, when a Microsoft Exchange Client user opens a folder, Microsoft Exchange Client displays only the views that have been saved in Microsoft Exchange Client format.
·	Custom field types. No Outlook custom field types, such as formula and combination fields, are viewable by Microsoft Exchange Client users. 
·	Rich text in message. Like Microsoft Exchange Client users, Outlook users can format message text by using rich text attributes such as bold, italic, and indent. 
·	Attachments. Outlook can open attachments or objects within messages created by Microsoft Exchange Client users, and vice versa. Outlook and Microsoft Exchange Client users can also attach a message to another message. Outlook users can also attach other Outlook items (such as a contact) to their messages. However, Microsoft Exchange Client users receive the items as text-only attachments.
·	Embedded hyperlinks. If an Outlook or Microsoft Exchange Client message recipient clicks an embedded Web-style hyperlink (a URL address of an Internet or intranet Web site) in a message created by another Outlook or Microsoft Exchange Client user, the recipient's browser opens the appropriate Web site. 
·	Unlimited message size. Outlook and Microsoft Exchange Client users can create and read messages of any size (subject to available system resources). 
·	HTML-formatted mail messages. Outlook supports the ability to send mail that is formatted as HTML and also to create stationery by using HTML mail. However, Microsoft Exchange Client users cannot send mail formatted with HTML, and when they receive HTML messages, the messages are displayed as plain text without the original formatting.
·	Sending and receiving vCards. Outlook allows users to send and receive contact information by using the Internet standard vCard format. Microsoft Exchange Client does not support this feature. 
Using Public Folders
  
Outlook supports all the custom public folder view features of Microsoft Exchange Server. In fact, Microsoft Exchange Server does not distinguish between Outlook and Microsoft Exchange Client when users open a public folder. For this reason, Outlook and Microsoft Exchange Client users can gain access to a common set of public folders. 
Other Messaging and Collaboration Features
  
Some interoperability differences between Outlook and Microsoft Exchange Client features go beyond the basic capabilities of exchanging e-mail messages and using public folders. These additional feature differences include the following:
·	Rules. Microsoft Exchange Client has an interface to manage rules, called the Inbox Assistant. Outlook includes the Rules wizard, an enhanced rules user interface. The Outlook Rules wizard enables users to manage Inbox Assistant rules (server-side rules) in addition to their Outlook rules (client-side rules). The Rules wizard allows users to easily recreate (convert) Inbox Assistant rules into Outlook rules.
	Each time the Rules wizard is started, it checks for active Inbox Assistant rules on the user's computer. If any exist, the Rules wizard gives the user the option to convert them automatically to Outlook rules. After an Inbox Assistant rule has been converted to an Outlook rule, users can modify it at any time using the Rules wizard. 
	Note   The Rules wizard is a built-in feature of Outlook and is not available with the Microsoft Exchange Client. 
·	Forms. Forms created using the Outlook forms design environment can only be used by Outlook users. Forms created using the Exchange Forms Designer (EFD) can be used by both Outlook and Microsoft Exchange Client users. Forms implemented using Exchange Server HTML interfaces can be used by Outlook, but not by Microsoft Exchange Client. Developers should create forms using a tool that is appropriate for the mix of operating systems in the particular organization.  
	Microsoft Exchange Server provides an alternative means of creating forms for use in collaborative applications. It does this by using Active Server Pages and the Microsoft Exchange Collaboration Data Objects (CDO) interface to script forms that are displayed as HTML in a Web browser. Outlook supports Microsoft Exchange Server HTML forms. These features provide Microsoft Exchange sites with an option for developing electronic forms that can be deployed across all operating systems.
·	WordMail. Microsoft Exchange Client users can choose either Microsoft Word 95 or Microsoft Word 97 for WordMail. Outlook users, however, must have Microsoft Word 97 installed to create messages using WordMail (although they can receive and read messages composed with either WordMail 95 or WordMail 97).
·	Voting. With Outlook, users can easily create and send ballot messages to other Outlook users and track the voting responses automatically in Outlook. An Outlook user specifies the voting choices when creating the message, and then sends the message to other users. When recipients using Outlook receive a voting message, the selections they can vote on appear as buttons in the Outlook message—a recipient votes with just a mouse click. However, when Microsoft Exchange Client users receive voting messages from Outlook users, they receive only the text of the Subject line and the body of the voting message. No voting buttons are displayed.
·	Microsoft Exchange Client Preview Pane. Outlook has a built-in Preview Pane. The Microsoft Exchange Client Preview Pane is not compatible with Outlook, and is therefore not recommended for use with Outlook.
·	Tasks. When an Outlook user delegates a task to a user who is running Microsoft Exchange Client, the recipient receives only an e-mail message that lists the task's description, start and end dates, and other information as text in the body of the message.
Interoperability with MS Schedule+
  
Outlook and Schedule+ (16-bit version 1.0 and 32-bit versions 7.0, 7.0a, and 7.5) offer interoperability for basic calendar and group scheduling capabilities. In a mixed environment consisting of Outlook and Schedule+ users, all users can exchange meeting request messages and share calendar free/busy status with each other. However, many Outlook capabilities go beyond those of Schedule+. Outlook users should be aware that their co-workers who are using Schedule+ might not be able to view or use some of the messaging or calendar information the same way as another Outlook user would. 
Note   Outlook users with a Corporate or Workgroup configuration have the option to substitute Microsoft Schedule+ 7.x for the Outlook calendar function. See "Using Schedule+ As the Primary Calendar in Outlook" in Chapter 5. 
Basic Group Scheduling Capabilities
  
For most organizations, two scheduling functionality areas are considered essential: 
·	Exchanging meeting requests
·	Viewing free/busy status 
Outlook and Schedule+ interoperate completely in both of these key areas. 
Note   The Outlook driver for Schedule+ allows Schedule+ users to open Outlook users' calendars (read only) and view free/busy details; without this driver, users are unable to do so. To install this driver, see "Outlook Driver for Microsoft Schedule+ " in this chapter.
As you read this section, you should be familiar with the distinction between free/busy status and free/busy details: 
·	Free/Busy Status. The time blocks during which the user is either available for a meeting or is busy. When users publish their free/busy status, other users can view the free/busy time blocks (but not necessarily their free/busy details) from within the Meeting Planner. 
·	Free/Busy Details. The descriptions (details) of the appointments or activities a user has scheduled. Users who have been given at least Read-Only permission to another user's calendar can not only view (in the Meeting Planner) the time blocks representing when that user is free or busy, but they can also view the user's free/busy details.
Exchanging Meeting Request Messages
  
Outlook and Schedule+ 1.0 and 7.x users can freely exchange meeting messages across Windows and Macintosh platforms. Although Outlook users and Schedule+ 1.0 users can freely exchange meeting requests and responses, Schedule+ 1.0 does not recognize the advanced features of Outlook (such as attachments, the meeting location field, and recurring meetings). As a result, when a Schedule+ 1.0 user receives a meeting message from an Outlook user, Schedule+ 1.0 ignores any Outlook-specific message features it does not recognize. For example, if an Outlook user sends a recurring meeting request to a Schedule+ 1.0 user, the Schedule+ user receives only the first meeting request. 
Viewing Free/Busy Status
  
When users "publish" their free/busy status, other users can view the free/busy time blocks (but not necessarily their free/busy details) from within the Meeting Planner. With appropriate permission, Outlook and Schedule+ 1.0 and 7.x users can view each other's free/busy status (time blocks). 
In addition to designating free/busy status, Outlook users can designate "tentative" and "out of office" time blocks for specific appointments. When Outlook users view each other's calendars, they can identify the time blocks that are free, busy, tentative, or out of office. When Schedule+ users view an Outlook user's calendar in their Meeting Planners, time blocks designated by the Outlook user as tentative appear as free times to the Schedule+ users. However, time blocks designated by the Outlook user as out of office appear as busy times to Schedule+ users. 
Outlook differs slightly from Schedule+ in how it handles unpublished free/busy status. When Schedule+ users choose not to publish their free/busy status, other Schedule+ users—if they have at least Read-Only permission—can still view the users' free/busy status in their Meeting Planners. However, when Outlook users choose not to publish their free/busy status, other Outlook users—even those who have at least Read-Only permission—cannot view the users' free/busy status in their Meeting Planners. To view the users' unpublished free/busy status, Outlook users must view (open) the user's calendar, providing that they have appropriate permission. 
By default, Outlook 98 publishes two months of free/busy status for all users (the default value for Outlook 97 is three months). Users can change the number of months or choose not to publish their free/busy status at all (by specifying 0 months).To set the number of months of free/busy status that is published, click the Tools menu, click Calendar Options, and then click Free/Busy Options. In the Publish X Month(s) of free/busy information on the server box, enter 0 (zero).
Other Group Scheduling and Calendar Features
  
The following sections describe differences that exist in how Outlook and Schedule+ interoperate. 
Opening Other Users' Calendars
  
Unless the Outlook driver for Schedule+ is installed, Schedule+ 7.x users cannot open an Outlook user's calendar. As a result, Schedule+ 7.x users cannot view free/busy details of an Outlook user's calendar. To install this driver, see "Outlook Driver for Microsoft Schedule+" in this chapter; there are 16-bit and 32-bit versions of this driver (no Macintosh version is available). Outlook users, on the other hand, can open Schedule+ 7.x users' calendars with appropriate permission, and can therefore view a Schedule+ 7.x user's free/busy details. 
Viewing Another User's Free/Busy Details
  
Outlook users on Microsoft Exchange Server can view the free or busy details of Schedule+ users who are also on Microsoft Exchange Server, but they cannot view the details of those on Microsoft Mail Server. Schedule+ 7.x users can view the free or busy details of Outlook users when all users are on Microsoft Exchange Server and the necessary Windows 16-bit or 32-bit driver is installed; for more information, see "Outlook Driver for Microsoft Schedule+" in this chapter. Schedule+ 1.0 users cannot view Outlook users' free/busy details. 
Outlook users who have at least Read Only permission to another user's calendar can see when that user is free or busy. Also, they can view the description (details) of that user's scheduled appointments and activities in the Meeting Planner. 
Delegate Access
  
Just as they can give others permission to read or modify their folders, users can designate other users to be their "delegates." As a delegate, a user can manage the owner's e-mail and schedule, as well as create, send, and reply to messages (including meeting and task requests) on the owner's behalf. For example, managers could give their assistants or teams access to their schedules so the assistants or team members can create messages, appointments, tasks, or other items for them.
A delegate relationship requires that both users run the same scheduling client. For example, Outlook users can be delegates only for other Outlook users. Outlook users who want to participate in delegate relationships with other Outlook users must keep all their primary folders (such as Calendar and Inbox) on the server instead of on their local computers. 
Schedule+ 7.x users can designate other users to be their "delegate owners." As a delegate owner, a user has all the capabilities of a delegate, and can also designate additional delegates for the owner's schedule. Like Schedule+ 7.x users, Outlook folder owners can enable their delegates to give other users the necessary permission for gaining access to the owner's folders. However, Outlook does not allow a delegate to designate additional delegates for the owner's folders. To designate a delegate in Outlook, you must be logged on as the folder (account) owner. 
Note   When Outlook is a client for a Microsoft Mail server, Outlook users cannot give other Outlook users access to their folders.
Direct Booking
  
If they have appropriate permission, Outlook users can take advantage of the Schedule+ direct booking feature to book appointments directly into a Schedule+ Calendar. However, Schedule+ 1.0 and 7.x users cannot book appointments directly into Outlook Calendars. In addition, Outlook users cannot book appointments directly into other Outlook Calendars. 
With direct booking, no meeting request is actually sent to the Schedule+ resource (unless the booking fails). The meeting organizer's client software just adds the meeting directly into the Schedule+ resource's calendar. If the direct booking fails, a meeting request is sent instead; if no one responds to the meeting request, the resource will not be booked.
Because a directly booked Schedule+ resource is unlikely to receive many meeting requests, you are not required to assign a delegate to the resource or have a continuously running computer logged into the resource's account to process incoming meeting requests. However, without a delegate or continuously running computer for the Schedule+ resource, if a user does send an explicit meeting request to the resource instead of booking an appointment directly, the meeting request goes unnoticed until a user actually logs on to the resource's account. However, with appropriate permission (such as Delegate), an Outlook user can open another Outlook user's or resource's calendar and modify it directly, if necessary.
Unlike Schedule+ accounts, Outlook accounts cannot be booked directly. Therefore, to process the meeting requests that are sent to Outlook resource accounts, it is recommended that each Outlook resource account be set up with a delegate that receives its meeting requests. The delegate account should be logged on to a continuously running computer. Because a single delegate can be responsible for multiple resource accounts, a single, dedicated "delegate computer" can handle a large number of conference rooms and other resources. 
Tasks
  
Outlook gives users new task features that are not available in Schedule+ 7.x or Schedule+ 1.0. For example, Outlook provides additional views for task items, making it easier for users to manage tasks in a way that best suits their needs. Also, Outlook enables users to delegate tasks to other users. When an Outlook user delegates a task to another Outlook user, all the task's information (such as start date, end date, and status) is sent as a special task request message to the recipient, who can add it to their own task list automatically. 
After Outlook is installed, users can import their Schedule+ 7.x or Schedule+ 1.0 task data at any time using the Outlook Import wizard. By default, Outlook imports Schedule+ task information into the Outlook Tasks folder. Users can choose to ignore or replace any duplicate entries encountered during the import process.
Contacts
  
Outlook provides a rich Contacts feature that helps users keep their business and personal contact information up-to-date. Although Schedule+ 7.x includes some contact features, many of the Outlook contact management enhancements, such as additional contact views, are not available in Schedule+ 7.x.
The enhanced Contacts feature enables Outlook users to include e-mail addresses with their contacts. Outlook users can import all Schedule+ 7.x contacts, as well as contacts stored in Microsoft Exchange Client personal address books (PABs). In addition, Outlook users can maintain contacts as their personal e-mail address books; they no longer need to maintain individuals' names and e-mail addresses in two separate places.
After installing Outlook, users can import their Schedule+ contact data at any time using the Import And Export command on the Outlook File menu. By default, Outlook imports Schedule+ contact information into the Outlook Contacts folder. Users can choose to ignore or replace any duplicate entries encountered during the import process. The Outlook Import wizard also imports Microsoft Exchange Client PABs.
Outlook Driver for MS Schedule+
  
With the Outlook driver for Schedule+ 7.x, Schedule+ users can open an Outlook Calendar from Schedule+ and view Outlook free/busy details. The Schedule+ user must have at least Read-Only permission for the Outlook user's calendar. Also, that calendar must be stored on the Microsoft Exchange Server.
Note   The Schedule+ user can only read the Outlook user's calendar, not add to it or edit it, regardless of the permissions granted by the Outlook user. 
This driver works on 16-bit and 32-bit versions of Microsoft Schedule+. Both the Schedule+ and Outlook users must be running Microsoft Exchange Server. The 32-bit driver is available with the Microsoft Exchange Server 5.0 and 5.5 CDs; you can also download this driver from the Outlook Web site at http://www.microsoft.com/outlook/.
The 16-bit driver is available only with the Microsoft Exchange Server 5.5 CD.
Installing the Driver
  
You must have installed Schedule+, Outlook, and either Windows 3.1, Windows 95, or Windows NT 3.51 or a later version.
To install the Outlook driver for Schedule+
1. 	If Schedule+ is open, close it.
2. 	In the same folder as your Schedule+ files, double-click Msoutl.exe (Windows 95 users) or Msoutl16.exe (Windows 3.1 users). 
3. 	When asked if you want to continue, click Yes. 
4. 	When the installation is complete, restart Schedule+.
	The following files are installed on your computer:
·	Msoutl32.dll
·	Msostubs.dll
·	Msoutl.inf
·	Unins351.reg
·	Readme.txt 
After the driver is installed, the Schedule+ user can open an Outlook user's calendar.
To open an Outlook user's calendar from Schedule+
1. 	On the Schedule+ File menu, click Open. 
2. 	Click Open Other's Appointment Book. 
Removing the Driver
  
If you no longer want the driver installed on your computer, you can remove it easily. The following procedure describes how to remove the driver if you are running Windows 95. If you are running Windows 3.1 and you need to remove this driver, you must run setup again. 
Windows NT 3.51 users can remove the driver by running Unins351.reg and then deleting Msoutl32.dll and Msostubs.dll. These files are located in the same folder as Schedule+.
To remove the Outlook driver for Schedule+ if you are running Windows 95
1. 	On the Start menu, point to Settings, and then click Control Panel.
2. 	Double-click Add/Remove Programs.
3. 	On the Install/Uninstall tab, click Microsoft Outlook 97 Driver for Schedule+, and then click Add/Remove. 
Known Issues
  
This list identifies potential issues with the Outlook driver for Schedule+ 7.x:
·	All-day events in Outlook appear as appointments when viewed in Schedule+ 7.x.
·	If you reinstall Schedule+ 7.x, you must also reinstall the driver.
·	An Outlook user might share his or her Outlook Calendar with other users and then switch to using Schedule+ 7.x as the primary calendar. In this case, Schedule+ 7.x users who are using the Outlook driver for Schedule+ 7.x to open that user's calendar will continue to open that user's Outlook Calendar instead of the Schedule+ 7.x Calendar. To solve this problem, the Outlook user needs to remove the permissions on the Outlook Calendar folder so that the Outlook driver for Schedule+ 7.x does not open the folder.
·	Outlook appointments with more than 32K of text in the Notes field appear to have a blank Notes field when viewed in Schedule+ 7.x. 
Interoperability with Outlook for Windows 3.1x and Outlook for the Macintosh
  
The Microsoft Outlook integrated e-mail client for the Windows 3.1x and Macintosh operating systems improves the messaging and group scheduling interoperability with Outlook 98 (for 32-bit Windows) without requiring new hardware. These versions are appropriate for customers with Microsoft Exchange Server who need "stepping stone" clients as they migrate to the 32-bit Windows operating systems. The Outlook clients for Windows 3.1x and Macintosh are upgrades from the Microsoft Exchange Mail and Schedule+ clients.
Customers committed to staying on Macintosh or 16-bit Windows platforms for the long term might consider Outlook Express for Macintosh or Windows 3.x for messaging, as well as Outlook Web Access (for Microsoft Exchange Server) for calendaring. Microsoft continues to support the Macintosh and Windows 3.x Microsoft Exchange Server mail clients, as well as Schedule+ for Macintosh and Windows 3.x.
The Outlook clients for Windows 3.1x and Macintosh include all the features of the existing Microsoft Exchange Mail and Schedule+ clients, plus new features to smooth interoperability with Outlook 98. Due to operating system and hardware limitations of typical computers based on 16-bit Windows and Macintosh, Outlook clients for Windows 3.1x and Macintosh continue to provide only a subset of Outlook 98 features. 
The following new features are included in the Outlook clients for Windows 3.1x and Macintosh: 
·	E-mail interoperability improvements. Users can now receive and send flagged messages, recall messages, and respond to (but not send) voting messages. Microsoft has also improved attachment handling and translation for Macintosh users. These clients are intended for Microsoft Exchange Server integration only and do not include Internet mail (POP3 or IMAP) support required to connect directly to an ISP. Users of 16-bit Windows and Macintosh who require POP3 support are encouraged to evaluate the Outlook Express client.
·	Calendar and group scheduling. By default, Outlook for Windows 3.1x and Macintosh can only view the free/busy information of Schedule+ 7.x users. Outlook for Windows 3.1x can read the details of a calendar on Outlook for Windows 95 using an add-on Schedule+ Exchange Transport .dll file, which is located in the \Support\MSOUTL\Win16 folder on the Microsoft Exchange 5.5 Client Pack CD; this feature is not available to Macintosh users at this time. The clients continue to have the same calendar, contacts, and task features available in Schedule+ version 7.0, and to display calendar, contacts, and task information in a separate window, accessible from the Outlook Bar.
·	Custom forms. Outlook for Windows 3.1x and Macintosh can display custom forms implemented with HTML and Microsoft Exchange Server Collaboration Data Object (CDO) scripts. When a user of Outlook for Windows 3.1x or Macintosh opens a custom form, it is displayed in the user's Web browser. HTML and CDO-based custom forms can be developed using the Microsoft Visual InterDev™ Web development system or any standard text editor and stored on Microsoft Exchange Server. The Windows 3.1x and Macintosh clients cannot design or display a custom form compatible with Outlook 98.
·	Improved visuals and interface. Outlook for Windows 3.1x and Macintosh includes a partially customizable Outlook Bar and a Folder Banner consistent with Outlook 98. Menu and toolbar commands are now arranged to match Outlook 98 more closely. 
Interoperability with MS Mail 3.x
  
In an environment where Outlook users must share information with Microsoft Mail 3.x for Windows users, all users can exchange e-mail with each other. However, because many Outlook capabilities go beyond those of Microsoft Mail 3.x, Outlook users should be aware that their co-workers who are using Microsoft Mail 3.x might not be able to view or use portions of the Outlook users' messaging information the same way as another Outlook user would. 
Although Outlook works with Microsoft Mail post offices, the full set of Outlook features is available only when using Outlook with Microsoft Exchange Server. The following Outlook features require Microsoft Exchange Server and are not available when Outlook is run on Microsoft Mail 3.x post offices:
·	Opening another user's e-mail folders as a delegate
·	Security on "Sent on behalf of" messages
·	Deferred delivery and message expiration
·	Digital signatures and encryption
·	Public folders
·	Full-text search
In addition, Microsoft Mail 3.x and Outlook cannot share the same message store. To use data from a Microsoft Mail 3.x message store, users must import the message store to an Outlook-compatible format. Microsoft Exchange Server includes a utility that imports Microsoft Mail 3.x message stores to MAPI format.
Exchanging Messages
  
In a mixed environment, Microsoft Mail 3.x users cannot take full advantage of many Outlook messaging features, including the following:
·	Enhanced standard message form. Microsoft Mail 3.x users who view messages created in Outlook can see the messages in the Microsoft Mail 3.x standard message form, which does not support the advanced features of the Outlook standard message form. As a result, some of the information in the Outlook message may not be viewable to Microsoft Mail 3.x users.
·	Extended message properties. When a Microsoft Mail 3.x user opens an Outlook message, extended Outlook message properties, such as voting buttons, are ignored, because they are not recognized by Microsoft Mail 3.x. This means that some messages created in Outlook may appear different to Microsoft Mail 3.x users. However, Outlook recognizes all Microsoft Mail 3.x message properties. 
·	Custom field types. No Outlook custom field types, such as formula and combination fields, are viewable by Microsoft Mail 3.x users. 
·	Rich text in messages. Microsoft Mail 3.x does not support rich text in messages. As a result, when an Outlook message with rich text is opened by a Microsoft Mail 3.x user, all rich text attributes are removed from the file and replaced by plain text.
·	Attachments. Outlook users can open attachments or objects within messages created by Microsoft Mail 3.x users and vice versa. When Microsoft Mail 3.x users receive a message that has another message attached to it, they can view the original message, but they cannot view the attached message. Outlook users can also attach other Outlook items (such as a contact) to their messages. Microsoft Mail 3.x users receive the items as text-only attachments.
·	Embedded hyperlinks. If a Microsoft Mail 3.x user opens a message that contains an embedded hyperlink, the hyperlink is displayed in the message as plain text only.
·	Unlimited message size. Outlook can create and read a message of any size (subject to available system resources); Microsoft Mail 3.x has additional size restrictions for messages. Although Microsoft Mail 3.x users may not be able to open a very large message created by an Outlook user, they can save the message to a file or print it.
·	HTML-formatted mail messages. Outlook supports the ability to send mail that is formatted as HTML and also to create stationery by using HTML mail. However, Microsoft Mail 3.x users cannot send mail formatted with HTML, and when they receive HTML messages, the messages are displayed as plain text without the original formatting.
·	Sending and receiving vCards. Outlook allows users to send and receive contact information by using the Internet standard vCard format. Microsoft Mail 3.x does not support this feature. 
Other Messaging and Collaboration Features
  
Some interoperability differences between Outlook and Microsoft Mail 3.x go beyond the basic capabilities of exchanging e-mail messages. For example, forms created using the Outlook forms design environment can be used only by 32-bit Outlook users. Forms created with the Microsoft Exchange Forms Designer (EFD) and forms implemented using Exchange Server HTML interfaces cannot be used by the Microsoft Mail 3.x client. As a result, developers should create forms by using a tool that is appropriate for the mix of operating systems in your organization.
Also, when an Outlook user delegates a task to a user who is running Microsoft Mail 3.x, the recipient receives only an e-mail message that lists the task's description, start and end dates, and other information as text in the body of the message. 
Interoperability with MS Project
  
Microsoft Project 95 users can assign tasks to Outlook users. However, if the Outlook recipients accept the tasks, Project 95 does not add the tasks to Outlook Tasks automatically. Project 98 offers additional integration with Outlook. From within Project 98, Outlook reminders can be set up and Project items can be journaled.  
The workgroup features of Project 98 integrate with Outlook similarly to how previous versions of Project integrated with Microsoft Mail and Schedule+. Team members who want to use these features need to install the workgroup setup routine (available from Microsoft at no additional charge). This setup routine allows team members to view the custom e-mail messages that Project 98 generates. Project managers can use the TeamAssign feature to send custom e-mail messages to team members and assign them to project tasks; these messages are received in the team member's Outlook Inbox.
After the team member has officially accepted the task and sent a response back to the project manager, the task is logged automatically in the team member's Outlook Task list. The tasks are grouped under a new category that corresponds to the project name. Then, the team member can keep track of the task status (using the percentage complete field in the task list) from within the Outlook Task list.
With previous versions of Project, project managers had to send TeamStatus messages to team members to request that the team members submit status reports. However, Project 98 adds a new menu item called New TeamStatus Report to the Outlook Tasks menu. This feature enables team members to generate and submit TeamStatus reports without waiting for the project manager to ask for them. When the team member chooses this command, a custom TeamStatus e-mail message is created and stored in the Outlook Inbox. If the team member has been tracking the task status in the task list, the status information is added automatically to the TeamStatus report. Users can just open it and send it to the project manager. In addition, they can use the TeamStatus message to track the task status and also to save and store it in the Inbox until they are ready to submit it to the project manager.