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The 640 MEG Shareware Studio 2
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The 640 Meg Shareware Studio CD-ROM Volume II (Data Express)(1993).ISO
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1992-08-28
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E-Mail Gateways:
Connecting LAN-Based Messaging to the World
by Brett Warthen
With all of the complex terminology and standards in the
current electronic mail market, it's easy to become confused
about selecting an e-mail system. The fact of the matter is
that e-mail has become a big business, and major software
companies like Novell, Lotus and Microsoft are all trying to
stake a claim on portions of the market.
As IBM once proved when they dominated the mainframe computer
market, the marketing technique of FUD (fear, uncertainty and
doubt) can be incredibly effective when the target market has
a limited understanding of an environment. In this article,
we'll try to clear up the FUD, by explaining the terminology
and discussing many solutions that are available today for
connecting LAN-based messaging to other e-mail systems.
LAN-Based Messaging: Defining the Players
LAN-based e-mail is divided into at least 3 major camps:
Novell, Lotus, Microsoft.
Novell is unique, in that they are not providing an e-mail
front-end as part of their solution. Instead, they are
concentrating on back-end e-mail transport engines that are
supported by a growing number of "front-end" e-mail vendors.
When discussing LAN e-mail, we often use terms like "front-
end" and "back-end". The "front-end" or "user agent" is the
application that allows you to compose, read and reply to
messages. The "back-end" or "mail transport engine" is the
application that provides mail delivery services and transport
services between systems. Essentially the user agent submits
messages to the transport engine with requests for delivery,
and the transport engine delivers any incoming messages to the
user agent.
Novell's mail transport strategy is two-tiered. The basic
product, NetWare MHS (short for Message Handling Service) is a
DOS-based messaging store and forward engine, originally
developed by Action Technologies as a transport service for
their Coordinator electronic mail product.
MHS and its Standard Message Format (SMF) API specification
are currently supported with over 150 commercially available
products. Through the SMF interface, numerous e-mail
applications can easily exchange mail, including Infinite
Technologies' ExpressIT!, NoteWork Corporation's The NoteWork,
Da Vinci Systems' eMail, BeyondMail from Beyond, Inc., and
more.
NetWare Global Messaging (NGM) is an NLM-based (NetWare
Loadable Module/sever-based) messaging store and forward
engine that Novell is in the process of introducing. NGM will
be backward compatible with MHS 1.5, and Novell plans to offer
add-on connectivity modules for other environments including
SMTP, X.400 and SNADS. However, there are third party
gateways available for MHS today that provide connectivity to
these environments. If you require this additional
connectivity now, it may be prudent to explore the current
market alternatives.
Lotus and Microsoft are both essentially user agent vendors,
selling electronic mail products, also based on technologies
acquired from other companies.
However, Lotus cc:Mail and Microsoft Mail both provide their
own message transport services together with the user agent
portion. These transport services typically lack the range of
third party support that exists for the Novell MHS
environment. To a large extent, these environments are less
open for third party enhancements.
Ironically, if you want to connect a Lotus cc:Mail e-mail
system to a Microsoft Mail e-mail system, Novell's MHS is the
most convenient common ground, as both products provide
gateways that connect with Novell's MHS.
Similarly, WordPerfect Office (WPO) from WordPerfect
Corporation uses its own proprietary transport mechanism. A
growing number of WPO users are using the WPO to MHS gateway
option and MHS as a transport mechanism between sites, as it
is more widely supported.
Recent studies by the Electronic Mail Association estimate
that 60% of LAN-based electronic mailboxes are serviced by
Novell's MHS as the primary transport service, clearly
supporting the position that MHS has become the de facto
standard for LAN-based messaging. Contrary to a common
misconception, MHS is available for both Novell and other DOS-
compatible networks.
Access outside of the LAN environment is most often
accomplished through third party MHS gateways to X.400, SMTP
and various public mail services like CompuServe and MCIMail.
Vendors like Microsoft, Lotus and WordPerfect also provide
their own suite of gateways specific to their products.
LAN-Based Messaging: The Battleground
The current battleground in the LAN-based messaging
environment is over the APIs (Application Program Interfaces)
that are used for communications between e-mail front-ends and
their back-end engines.
Novell's NetWare MHS and NetWare Global Messaging define an
interface called the Standard Message Format (SMF), which is
how an application interfaces to the Novell Messaging Engines.
Novell publishes a "NetWare SMF Solutions Guide" that lists
third party products supporting SMF. Instructions on
acquiring this guide are included at the close of this
article.
The SMF specification is often times criticized by developers
because it provides only a directory and file based interface
for message submission and receipt. In other words, message
files are created following the SMF format, in specific
directories.
Three different versions of the SMF interface are currently in
existence:
SMF-64 (MHS 1.1 native interface, circa 1988) is limited to 8
character user and workgroup names, one file attachment per
message, and one recipient per message.
SMF-70 (MHS 1.5 native interface, circa 1991) supports up to
64 file attachments per message, and up to 64 recipients in a
single transmission instance of a message.
SMF-71 (NetWare Global Messaging and MHS 2.0, circa 1992)
breaks the 8 character user and workgroup name limitations and
lifts the limitation of 64 recipients in a single message.
(NOTE: At the time of this writing, MHS 2.0 is not yet
shipping, and MHS 1.5 is still the current version of the DOS-
based engine.)
Lotus and Microsoft have announced competing procedural APIs
for access to their message transport services. Procedural
APIs define function calls (DLLs in the Windows and OS/2
environments, linkable libraries in the DOS environment) that
applications can call from higher level languages for
messaging related functions.
Both the Lotus and Microsoft specifications are intended to
allow front-ends to access a variety of different message
transport engines. This would have the largest effect on non-
messaging applications that could include messaging as another
function within the application.
The Lotus specification, called VIM (Vendor Independent
Messaging, also sometimes jokingly known as Vendors Ignoring
Microsoft) was endorsed by Novell, Borland and Apple, with
limited endorsement from IBM. VIM grew out of the OMI (Open
Messaging Interface) introduced, but never delivered, by Lotus
in 1991. VIM libraries are planned for the DOS, Windows and
OS/2 environments.
The Microsoft specification, called MAPI (Messaging
Applications Programming Interface) is a Windows-centric API
that will be included with future versions of the Windows
product. The idea is to provide messaging services to Windows
applications, independent of the messaging transport service
installed.
At this stage, both VIM and MAPI are specifications waiting
for libraries to enable application developers to begin
sending messages through these APIs. Novell has also pledged
that both the VIM and MAPI specifications will be supported by
Novell messaging engines.
Mail enabled applications are an extremely exciting idea, and
with the macro language flexibility of popular Windows
applications like WordPerfect for Windows, Ami Pro, Microsoft
Word for Windows, Microsoft Excel, and more, why should we
have to wait for VIM or MAPI?
Indeed, creating a message in the SMF format may be difficult
from within a Windows macro, but several of the vendors of
MHS/SMF-based e-mail front-ends provide messaging services
that can be called via macros in Windows applications. So, if
you're in one of these applications, you can easily invoke a
macro through a menu option or button bar to send the current
document, or the selected text.
Da Vinci Systems' eMail for Windows defines a set of DDE
(Dynamic Data Exchange) functions that other applications can
invoke to send messages via MHS.
Finansa's WinMail and Infinite Technologies' ExpressIT! for
Windows include DLLs (Dynamic Link Libraries) that can be
called by any application or macro language for sending a
message via MHS, without the limitations of an active DDE
link. The Infinite DLL is also available as a separate
product, SendIT! for Windows.
In the DOS environment, free utilities like SendIT! from
Infinite Technologies make it easy to submit messages in the
SMF format.
Novell MHS and Third Party Gateways
MHS provides e-mail transport services between LANs and remote
systems over asynchronous dial-up links, bridged LANs
(internetwork connections in MHS terminology), and via public
hub services like Novell's NHUB service and the CompuServe/MHS
hub option.
Novell NHUB is a public hub service provided free of charge by
Novell (408-473-8989). MHS hubs can connect to each other
through NHUB, using NHUB as an intermediary hop. MHS hubs
must dial the NHUB phone number in San Jose, California in
order to send or receive mail through this service.
Presently, there are between 750 and 1000 MHS hubs that are
registered for this service.
The CompuServe/MHS hub is a surcharged public hub service
provided by CompuServe, Inc (614-457-MAIL). Thanks to
CompuServe's extensive data network, CompuServe provides local
phone numbers for dial-up access in most areas of the United
States, as well as a growing number of international access
points. Additionally, the CompuServe/MHS hub service provides
access to CompuServe Mail accounts, internet addresses, AT&T
Mail and AT&T Easylink, as well as FAX services.
The MHS product also defines a gateway interface to allow
third party gateway products to provide delivery services to
other environments. When MHS receives a message that is
addressed to an installed gateway process, MHS will load the
defined gateway process to perform e-mail delivery.
When connecting your LAN-based messaging system to the outside
world with gateways, it's important to evaluate all
alternatives, as there are usually several different ways to
get from here to there.
For example, if you want to connect your LAN to the Internet,
you could choose an SMTP or UUCP gateway, or you could use a
commercial service like the CompuServe/MHS hub.
Third party gateway products exist to provide connectivity to
the following environments (to name but a few):
SMTP - An SMTP gateway requires a dedicated active link to
the internet, which is generally an option only for
universities, federal government agencies and defense
contractors. SMTP gateway services are provided by
Computer Mail Services' S-Bridge (313-352-6700) product,
and a shareware product named XGATE (download XGATE.ZIP
from PCVENF Library 13 on CompuServe or use the keyword
XGATE with Library @ Infinite).
UUCP - A UUCP gateway connects MHS to a Unix host using
UUCP over dial-up or dedicated asynchronous lines. Using a
popular shareware gateway named UGATE (download UGATE.ZIP
from PCVENF Library 13 on CompuServe or use the keyword
UGATE with Library @ Infinite) to dial into the UUNET
service is an inexpensive way to gain connectivity with the
internet. NoteWork Corporation (617-734-4317) also
connects the MHS and UUCP environments with The NoteWork
MHS/UUCP Gateway.
Internet - SMTP and UUCP gateways can be used to gain
connectivity with the internet. Additionally, the
CompuServe/MHS hub service provides connectivity to most
internet addresses, and is a viable option for low volume
mail exchange with internet addresses.
X.400 - X.400 is the accepted international standard for e-
mail connectivity between computer systems, and can be
effective when many different types of computer messaging
systems must be interconnected. X.400 gateway services are
provided by Retix (213-399-2200), Touch Communications
(408-374-2500) and Frontier Technologies Corporation (414-
241-4555). With NetWare Global Messaging, Novell will also
soon be providing an optional X.400 connectivity module.
However, costs for X.400 gateways, which range between $10
to $20 thousand and up, are not within the budgets of most
LAN systems. This cost becomes even more expensive when
you consider that X.400 is generally not a standard feature
on other computer systems, and must be purchased as an
additional cost option. For the majority of situations
today, direct gateway solutions between environments are
more cost effective and less complicated to install and
maintain.
IBM SNADS, PROFS, Office Vision - IBM Mainframe
connectivity is available from Novell with their Messaging
Connect product, as well as gateway services from
SoftSwitch.
AS/400 - Blue Rainbow Software (206-357-8971) provides a
gateway between MHS and Office Vision/400 on an IBM AS/400
midrange computer.
VAXMail, DEC All-in-One - Connectivity to DEC VAX based e-
mail systems is available through products from Joiner
Associates (608-238-4454) and Xitel (215-647-2866).
Wang Office - Lightspeed Mail Gateway from MacSoft (805-
324-4291) provides e-mail exchange between MHS and Wang
Office.
MCIMail - For MCIMail connectivity, M-Bridge from Computer
Mail Services (313-352-6700) is available.
AT&T Mail - NoteWork Corporation (617-734-4317) offers an
MHS to AT&T Mail gateway, A-GATE for MHS, while similar
connectivity is offered through the CompuServe/MHS hub
service.
FidoNet - For connecting FidoNet based bulletin boards with
MHS, there is a shareware product named FidoGate (download
FIDOGT.ZIP from PCVENF Library 13 on CompuServe or use the
keyword FIDOGATE with Library @ Infinite).
Thanks to Novell's relatively open specifications for defining
gateway processes, there are also quite a few third party MHS
gateway products that provide non-traditional extensions to e-
mail capabilities.
Message Forwarding agents allow messages sent to one
address to be forwarded or copied to another address
without requiring user intervention, which is useful for
traveling users or users who must temporarily receive their
e-mail at another location. (ForwardIT! from Infinite
Technologies 410-363-1097, Da Vinci Assistant from Da Vinci
Systems 919-881-4320)
Alpha Numeric Paging gateways, such as PageIT! from
Infinite Technologies (410-363-1097), provide the ability
for messages to be sent via electronic mail to alpha
numeric (full text) pagers. Salesmen and service
technicians can receive their e-mail easily while out of
the office, and receive additional information on phone
calls and service calls.
Remote File Retrieval utilities, like MHS Librarian from
Infinite Technologies (410-363-1097), allow users to
request files and other data through e-mail requests,
providing bulletin board type capabilities on top of store
and forward e-mail systems.
Discussion Lists are another name for the type of service
provided by the popular List Servers on the internet.
Essentially, users are allowed to subscribe to a list,
generally by an e-mail request for subscription, and any
messages sent to the list address are automatically
rebroadcast to the list of subscribers. In the MHS world,
popular discussion lists include LIBRARY @ NOVELL (send a
request with GUIDE for more information) and LIBRARY @
INFINITE (send a request with INDEX for more information,
or SUBSCRIBE to subscribe). Both of these lists are
available through the CSERVE and NHUB public hubs (LIBRARY
@ NOVELL requires that your host be defined to NHUB).
The LIBRARY @ INFINITE service was built using the MHS
Librarian product from Infinite Technologies (410-363-
1097).
The LIBRARY @ NOVELL service is a customized application
built using the rules and message filtering capabilities of
BeyondMail (617-621-0095) in conjunction with the
Distributor product from WorkFrame, Inc. (617-491-4678)
Voice Mail links to e-mail systems are provided by a number
of innovative products from VoxLink (615-297-4271). E-mail
messages can be converted to voice mail messages, and voice
mail messages can even be sent via e-mail and played over a
PC speaker.
Print Job transmission between sites is provided by a
unique application called MhsQ! by Infinite Technologies
(410-363-1097). Essentially, e-mail jobs sent to a NetWare
print queue on one system can be automatically compressed
and transmitted via MHS to another site where they are
printed. Admittedly a unique application, MhsQ!
illustrates some of the open-ended possibilities for
extending MHS with gateway processes.
FAX gateways are provided by quite a few vendors. At a
minimum, these products provide the ability for users to
submit out-bound FAX requests through MHS e-mail. More
advanced systems also support the ability to route in-bound
FAXes to MHS mailboxes for viewing. Two of the most
popular products in this market are the Optus FacSys (908-
271-9568) and Castelle FaxPress (408-496-0474).
MHS gateway possibilities don't stop with these. For more
information on developing your own custom MHS gateways, Novell
publishes the "NetWare SMF Programmer's Reference".
Additionally, a utility called RunIT!, that ships with the
Infinite Technologies' MHS Scheduler product also allows you
to easily create your own batch files that run as MHS
gateways, allowing tape backups or other automated tasks to
run on the MHS server.
What to Choose?
By this stage, it should be apparent that I am a strong
believer in the Novell Messaging environment, and the
complimentary third party products and utilities developed for
this environment.
It is no secret that my company has made a significant
investment in producing products for this environment.
However, we chose MHS because of its openness, widespread
third party support, and the overall flexibility of the MHS
environment.
First and foremost, I am an e-mail user requiring wide area
connectivity to allow my business to communicate with
distributors, resellers, end-users and other industry
contacts. I chose the MHS platform for my business, because
thanks to third party gateway support, it was the only
solution that could adequately fit these needs.
==================================================================
Brett Warthen is President of Infinite Technologies in Owings
Mills, Maryland, a software development company specializing
in electronic mail and add-on utilities for e-mail systems.
Brett is also a volunteer sysop on the Novell NetWire family
of forums on CompuServe. You can reach Brett via e-mail at
the following addresses:
MHS: Brett @ Infinite (via CSERVE or NHUB)
CompuServe: >MHS:Brett@Infinite
Internet: Brett@Infinite.mhs.compuserve.com
FAX: +1-410-363-3779