E-mail Task Force Report

 

The existing E-mail system, Pathworks Mail, was developed by Digital Equipment Corporation (DEC) in the late 1980s and has been used at City University since 1991. The software is DOS-based and integrated into the network operating system DEC Pathworks on CTNET.

However, E-mail technology has grown rapidly over the last few years. Many powerful and user-friendly E-mail packages have come onto the market. Since the Windows system has become more popular, most new E-mail systems are ported into the Windows environment to use its user-friendly interface.

Due to these changes, the Computing Services Centre (CSC) wished to choose a suitable Windows-based E-mail package for a campus-wide E-mail system. In July 1994, a task force was formed to evaluate selected popular E-mail packages: Lotus cc:Mail, Microsoft MS-Mail, and DEC TeamLinks.

Criteria

The goal of the task force was to compare the functionality of each selected system on User Interface as well as System Administration. To balance the two considerations, we decided that the system should:

1. Be easily adopted by the majority of users in the University;
2. Easily communicate with the outside world (via Internet);
3. Provide good PC LAN access, but not necessarily be a LAN-Based system;
4. Provide a user-friendly interface in both a DOS and Windows environment;
5. Conveniently manage a large number of user accounts and user groups;
6. Provide good system security, data backup and recovery.

Due to limited time and resources, only the major models and features of candidate E-mail packages were tested and evaluated. All evaluation was performed under the Pathworks 4.1 network environment.

Overview of Candidate E-mail systems

Lotus cc:Mail and Microsoft MS-Mail are the most popular PC LAN-based E-mail systems. Both run in "shared file access mode" in which all users invoke the E-mail software to access the same shared file area located on a network server to manage, transfer, and exchange E-mail. Each shared file area stores account information as well as messages for a group of users forming a Post Office. This shared file area is a domain of management and managed by the administrator with special administration utilities. There is no independent "server" process or program running on the server side.

On the other hand, DEC TeamLinks is a host-based E-mail system running in true Client-Server mode. This means that the server program runs independently on a host computer, and controls all E-mail tasks such as message delivery, transfer and exchange. At the same time the client program on the PC side is responsible for message display and user interaction. Each user has an account on the server computer where his/her mailbox, containing account information as well as messages for him/her, is located. Users can also access their mailbox by logging into the server account directly and using the host client program (DEC Mailworks for OpenVMS).

Functionality Comparison

System Administration

• Mailbox management (message, account, storage)

As PC LAN-based E-mail systems, cc:Mail and MS-Mail store all users' messages in a shared file area which is opened in read and write mode by all users. By storing messages in a single encrypted file with pointers, cc:Mail takes less space than MS-Mail since the latter stores messages of different users in different files. On the other hand, MS-Mail users can transfer their mail to private mail folders located on the local storage while cc:Mail lacks this function.

Due to the limited power of a PC, one Post Office cannot hold too many users. For cc:Mail the maximum number of users for a Post Office is 300, while for MS-Mail it is 500. This means that several Post Offices have to be set up in a large organisation like our University. Such an arrangement complicates Post Office administration.

TeamLinks, on the other hand, has no equivalent concept of "Post Office", or we can also say that all users belong to one Post Office. Each TeamLinks user has an account on the host server computer for holding his/her messages. Therefore, the maximum number of users in TeamLinks only depends on the capacity of the host computer, which usually can support more than one thousand users. Subsequently, the account administration jobs can be fully integrated into the standard account management system on the server so overhead is minimal.

Like MS-Mail, TeamLinks also allows users to store their messages on local storage so that space in server storage can be freed. In addition, users can freely move their messages between local storage and the remote mailbox.

• Security and control ( protection, space control, backup)

Although both cc:Mail and MS-Mail store their messages in encrypted format such that even the administrator cannot read them, they can be damaged easily by any user because the database files are opened in read and write mode by all users. On the other hand, TeamLinks messages are stored in users' mailbox files which are protected by the host computer's standard file protection scheme. Only the owner and privileged users can access those files.

Since there is no space quota control for users of cc:Mail and MS-Mail, the administrator can only delete mail of one or more users which is older than a fixed number of days. An administrator can then do little to control the size of each user's mailbox and the entire database located in the central store. In TeamLinks, the space management is done by the server's operating system which can assign each user a disk quota. Users can be notified if their disk quota is lower than a threshold.

Data backup for cc:Mail and MS-Mail is done under DOS for each Post Office with vendor supplied utilities. Therefore daily and weekly backup operations for a large number of Post Offices takes a lot of time. For TeamLinks, the backup/restore job can be easily integrated into the standard procedures and schedules on the host computer.

• Outside Connection

As multiple Post Offices are required for cc:Mail and MS-Mail to handle a large amount of users, dedicated PCs are required to act as Routers (or MTA in MS-Mail) to communicate with different Post Offices. In addition, a dedicated PC is needed to serve as Gateway to connect to other E-mail systems on Internet.

Since there are no multiple post offices in TeamLinks, no extra hardware and software is required to handle communication inside the organisation. To get out to the Internet, TeamLinks requires Message Router software which has already been installed on the host computers for the existing system.

• Remote access

Since all TeamLinks users have accounts on the server, they can connect their host account via either modem dial-in (e.g. at home) or Internet's Telnet facility (e.g. at overseas university). They can then use the host Mailworks client - DEC Mailworks for OpenVMS - to access their mailboxes. For cc : Mail and MS-Mail however, special Mobile package is required for modem access. Moreover, they can not be accessed by Telnetting.

User Interface

• Basic Messaging

All three packages possess the following basic messaging features of a typical windows-based E-mail system:

1. User-friendly user interface;
2. "Reply All" feature;
3. Message searching capabilities;
4. New mail notification;
5. Address books and distribution list;
6. Binary attachment decoding within the same environment;
7. Built-in viewer to view attached files generated in different formats;
8. Context-sensitive on-line help.

• Advanced Messaging

Rule-based management is one of the advanced messaging features found only in cc:Mail. This feature provides a tool for automating the mail processing (e.g. auto-reply) based on criteria set by the user. This function is only available when the user is connecting.

While all three packages support Window's Object Linking and Embedding (OLE) feature, only cc:Mail provides the Dynamic Data Exchange (DDE) interface for Windows applications.

Both cc:Mail and MS-Mail provide a built-in spell checker, but cc:Mail's one is more sophisticated. There is no built-in spell checker in the current version of TeamLinks, but the vendor claimed that there will soon be one in the new release, version 2.2.

Directory services is another advanced messaging feature which enables a user to look up E-mail addresses by entering the name of the recipient. This feature is available in all three packages.

Conclusion

Electronic Mail is an important productivity tool that can save time and money. However, if we choose an E-mail package on user features alone, it might end up costing more money than it saves.

Although not as good as cc:Mail or MS-Mail in advanced messaging features, the user interface of TeamLinks is good enough for normal users or even beginners, as many user-friendly features available in most PC-LAN based E-mail packages are also available in TeamLinks. In addition, the system administration and maintenance tasks are easier to perform and control because they can be integrated into standard management processes on the host computers. The system file protection is stronger as well. Lastly, connecting to Internet requires no extra hardware and software.

Computing Services Centre City University of Hong Kong ccnetcom@cityu.edu.hk