Keeping your mail server running may not be that exciting, but as soon as it stops, you'll know about it right away.

A mail server may not be the most glamorous bit of software you can imagine, but most users regard e-mail as one of the more important services provided by the Internet, if not the most important.

Very few businesses could effectively run in today's corporate environment without e-mail, in fact it's the preferred method of communication for many. An e-mail is timely, but unlike a telephone conversation you have those crucial few minutes or seconds to weigh and word your response; and can always come back to it in a few minutes if you're too busy.

It's interesting to note that e-mail servers were originally developed for mainframe Unix systems connected over the Internet (or its predecessors), and that e-mail started to take off over corporate workgroups in the early 90s.

When corporate e-mail systems were connected to the Internet in the mid-90s, the real explosion took place. You can be certain that no matter how high your e-mail volume is now, it will continue to increase at an alarming rate.

So when making your choice, look for some scalability in your software and the all-important hardware; in particular make sure you have room for growth in terms of storage space and that you have no nasty I/O bottlenecks.

Another area worth thinking about is the mail server's ability to scan e-mail for viruses and deal with annoying spam. These features are still in their relative infancy and many of the vendors currently provide solutions as plug-ins, although there are quite a few with native abilities in this regard.

Either way, it is certainly worth considering when you are about to make your mail server purchase.

The most common mail protocols are SMTP, POP3, MIME, and IMAP, and your mail server should be capable of all these. There are also emerging protocols such as ESMTP and APOP, and as security requirements grow, encryption protocols such as SSL and RSA are also becoming important.

Many controls have now been added to these e-mail server packages to stop spammers using your mail server to send out bulk e-mail and thereby wasting your operation's time, money (bandwidth), and resources.

As for incoming spam, there are several organisations to help with these issues. One of the primary ways of achieving this objective is to use a blacklist to effectively block the IP and/or Internet domain name that spam messages have been known to emanate from. One of the many blacklists can be found at www.arachnoid.com/lutusp/antispam/spamdomains.txt.

The use of these blocking lists must of course be balanced with allowing legitimate e-mail through. The blocking of legitimate e-mail can be just as damaging to your company as letting spam through.

Some blacklists are run by self-appointed crusaders against spam, who can be somewhat over zealous in blocking out mail servers. Major Australian ISPs have found themselves at the sharp end of these policies on several occasions.

The April 2002 issue of ZDNet Australia's Technology & Business Magazine contains reviews of mail server packages, including Editor's Choice Awards for the best products. For subscription information, visit Technology & Business.

Ipswitch Imail V7.0

The developer claims the software is easy to install and we heartily agree; we had it up and running in a matter of minutes. Adding users and giving them access using POP3 and SMTP or even through IMAP4 and a Web browser was easy, although setting up spam filters was a tad more time consuming.

We downloaded the trial version from Ipswitch's Website where you can also buy the package online. Prices start at AU$2216.50 for 250 users, but this does not include a support contract. We feel the extra AU$2871 for a service contract is money well spent. The service contract includes 12 months of major product upgrades and telephone and e-mail tech support.

An unlimited user license weighs in at AU$5555 (without contract) which is still very reasonable. Ipswitch claims Imail will cope with over 100,000 users on a grunty server, and we would certainly be comfortable with at least tens of thousands of clients.

On the topic of hardware, Imail will run on surprisingly little. If you only have a couple of hundred users, you could probably dust off the old low-end Pentium NT server you have sitting in the back room.

As long as it has more than 64MB of memory and a couple of gigs of disk space, it should work fine. Realistically, however, you would probably want a bit more grunt.

For all but the largest applications a moderate Pentium III system would be sufficient. As with all mail servers, though, the more memory and hard drive space you have, the more efficiently the software will run.

As mentioned, there is an antivirus option for Imail, which we did not test, and which is rather expensive--AU$15,004 buys you unlimited user licenses for the antivirus plug-in, 12 months of upgrades and product support. You can score a better deal by bundling user licences, service agreements and antivirus support all together for AU$17,314.

Imail Administrator has a similar look and feel to Exchange's admin tree structure, however the tree is better pruned than Microsoft's. As a consequence, navigating and configuring options is certainly easier. Even though the interface lacks the depth and functions of Exchange, it nevertheless gets the job done.

Imail's console application can be run remotely and has the ability to connect to multiple servers, a very attractive feature if you have servers in more than one location. Imail has built-in monitoring which includes SMTP, POP3, WWW, news, DNS, external router, and disk space. The software can be configured to restart a service automatically and/or notify the administrator by pager or e-mail (the administrator can then remotely restart services manually if required).

Security is quite well supported with SSL, user authentication, exchange of encrypted passwords with APOP or CRAM-MD5, and the ability to block mail from selected IP addresses or domains. While mail relaying from external sources can be blocked, local users can be allowed to relay, where the term "local user" can be defined and configured by the administrator.

In addition to the useful Web mail access, Imail Server includes Web calendaring based on the ICAL standard, so the user can receive a meeting notification from any compliant client and import it directly to their calendar. Although we must admit that Imail's supplied Web e-mail client is fairly basic and not as refined as Exchange's, it's good that it provides this functionality.

Lotus Domino V5.0.9

The server behind Lotus Notes is Domino. Domino and Notes are not renowned for ease of installation and configuration; but to be fair, both are very powerful entities.

Notes is much more than a simple e-mail client, and at the same time, Domino is certainly more than just a mail server. It is the foundation on which you can lay other applications such as Domino.Doc. As its name suggests, Notes/Domino is a highly evolved document management system.

Even taking this into consideration we feel the installation and configuration of Domino could be simpler. If you want to ensure Domino is easier to administer, you need to install the server and then separately install Domino Administrator. While Domino is not difficult to install, the process is more long-winded than either Imail or Exchange.

The vendor's minimum system configurations appear a tad conservative, or should that be optimistic. Under Windows 2000 for example, the minimum configuration is just 128MB of memory and 2GB of hard drive space.

We didn't test this configuration, but it's a fair bet that with those specs, Domino would struggle with even the lightest of e-mail loads. It was also interesting to note that although Domino runs under Windows 2000, the Web site states it has not been certified under this OS.

Domino is actually significantly less expensive than Exchange particularly if you intend purchasing the iNotes web-messaging client licences rather than the Notes messaging client licences.

Lotus does not directly supply antivirus solutions, but these are available from third party vendors such as Symantec, Trend, and McAfee.

Install Domino on its own and all you are presented with is a command-line interface that is even scarier than the Linux packages. Installing the Administrator package will have you sighing with relief, at least until you check out the incredibly complex menu structure.

While we think Exchange's menu structure could stand some pruning when compared to Imail, Domino could do with a jolly good logging. Yes, the Administrator is very powerful but until you get a handle on it, it will prove a tad daunting.

The configuration and set-up of the Web mail system under Domino was unnecessarily complex, compared to the almost default installs achieved by both Exchange and Imail.

The documentation is an absolute must! We didn't receive all the documentation and without the two volumes outlining the administration, flicking back and forth to the online help when trying to carry out even the simplest task is a pain.

Obviously the interface was made more challenging by the lack of docs, but even so most of the basic configuration tasks are painfully long-winded when compared to Exchange or Imail. Basically Domino tries to be everything to everybody and a lot of the functionality and complexity is totally unnecessary for a mail server.

If remote access is critical to your operation, then it would be advisable to purchase the Domino version that runs under Linux. We can see that the Windows server shortcomings as previously mentioned would also be applicable here.

As for protocols and security, we found that Domino supported most in one way or another along with its native Notes format.

Lotus has support packages ranging from web and telephone support during business hours, through 24x7 phone support, to on-site support plans which may include Lotus staff contracted on a weekly or monthly basis. Many Lotus/IBM business partners also provide support packages for Domino.

Microsoft Exchange 2000 Enterprise Server V6

However, if your needs extend to multiple databases per server, four-way clustering, and unlimited database size and storage, then Exchange 2000 Enterprise is the one you need. We were supplied with Exchange 2000 Enterprise Server for our testing purposes.

As far as Microsoft's minimum system requirements are concerned, while not a fantasy, they are pretty unrealistic if you actually intend your mail server to do any meaningful work.

However, our test system, the Dell PowerEdge 2250, was certainly more than adequate. Your choice of operating system for the server is pretty limited with Windows 2000 Server SP1 and above your only choices.

Like many Microsoft products, you need to buy the server software and then fork out for additional client access licences (CALs). Exchange 2000 Server is an inexpensive AU$1647, while Exchange 2000 Enterprise is AU$9572. CALs start off at a steep AU$161 per user but there are volume discounts. Antivirus support for Exchange from third-party vendors is extensive and a full list can be found at Microsoft's Web site.

Installation was not loathsome, but was certainly more long-winded than Imail. Because RMIT is a Netware based institution, we fell into a couple of simple traps that slowed us down. Exchange requires a Domain Server and Active Directory services. Given its capabilities, this makes sense, but since we didn't have either of these, we had to set them up before Exchange would install.

Exchange's default security settings were a curious mix. On install it's set to all relaying disabled, integrated Windows Authentication enabled, no size limits on sent or received messages, and a maximum recipient limit of 5000.

The former is a good out-of-the-box security feature as long as the administrator is aware that this is in place. Otherwise time will be wasted pondering why e-mail cannot be sent or received. On the other hand, not limiting e-mail size potentially allows e-mail viruses through, and spammers would be delighted to find a server that sends 5000 messages at a time.

The standard mail protocols such as POP3, IDAP4, and SMTP are supported, as well as secure messaging with SSL, X.509, and S/MIME. Mail relaying can be confined to internal users or domains.

Although the server has no native anti-virus capabilities, there are plenty of third party plugs to satisfy this requirement. Setting up e-mail filters is straightforward and simple. Anything from a single e-mail address to an entire Internet domain can be filtered with just a few clicks.

Setting up Web access was easy; in fact it is installed as default. However, the configuration needs to be adjusted partly through Exchange System Manager and partly through IIS. Of course if you use Microsoft's own client Outlook, then the setup is a no brainer. You can also access e-mail through mobile phones and pocket PCs.

The admin tools are integrated in the Microsoft Management Console (MMC) and the MMC can be remotely accessed with Windows 2000 Server's Terminal Services. The admin tools can also be installed on a remote "client" computer. Third-party management tools are also available.

Exchange's admin interface, called System Manager, is pretty simple to use and utilises a tree structure to access relevant functions. There are quite a lot of branches on the tree so remembering exactly where an item may be located can take some familiarisation.

Most of the time it's quite logical. Logging options are virtually unlimited should they be required for troubleshooting or reporting, and again they are very simple to activate.

Microsoft has several assisted support offerings, but the one most applicable to this product would probably be the Premier support plan for Enterprise. Amongst other feel-good services, this option provides round-the-clock technical support.

Qmail V1.03

The idea was to make a mail server that could be understood and configured by mortals. In some ways it succeeded, in others it fell quite short.

We feel the author applied the razor a little too liberally to some of Sendmail's more useful features such as relay controls and forwarding. At least the cost of Qmail is very price competitive--it's free.

We installed Qmail under Slackware. If you are comfortable finding your way around Windows, but are not familiar with Linux/Unix then our advice is forget it! Unless you have some Unix background, the command-line interface (CLI) and esoteric Unix commands will have your head spinning in no time.

Installation is where Qmail really falls down. The Windows-based mail servers run rings around it, and even Sendmail under Linux installs much less painfully.

Some of the installation instructions for Qmail have even seasoned Unix users running a decryption algorithm through their heads to try and make sense of them.

Obviously configuring filters is not as simple as clicking on a couple of buttons. You must use the CLI to pass commands and their parameters to the program as it starts, or make edits to numerous configuration files.

It's quite obvious that only your network administrator and some of their support staff will be configuring and adding new users for example; it's not a task just anyone can carry out.

Given its small size--216kb in TAR format and 1.1MB in Red Hat RPM format--and extremely efficient code, it's certainly going to handle far more users and traffic than Windows-based software.

For example, the author claims Qmail can cope with dozens of simultaneous deliveries on an old 16MB 486. So what can Qmail cope with? There are plenty of examples of large entities relying on the package, such as Ohio State University, PayPal, and Hotmail (outgoing e-mail). An e-mail outsourcing service called Critical Path runs 15 million mailboxes using Qmail.

Another advantage of a Unix-based mail server is that the operating system is robust and was designed from the ground up to be a network operating system.

As a consequence, you can just about leave the server up forever and don't have to worry about such problems as memory leaks. Qmail will not run on Windows--I can hear quite a few murmured "so whats"--but it will run on just about every flavour of Linux/Unix under the sun.

OK, so what do we do about the missing bits or features? Being open source means that if users had a strong enough hankering for the feature, they generally wrote it themselves.

Being the sharing people that Linux users are, they would then post it up for the world to access for free. In this was you can get additional functionality such as the rather necessary (in our opinion) mail relaying controls and forwarding, as well as other niceties like POP3-based authentication CRAM-MD5.

If you're lucky enough to own a Cray, there are even patches to run Qmail on UNICOS. And, as far as e-mail virus checking goes, we found two products: Qmail-Scanner (aka scan4virus) and AmaViS. These can be had for the princely sum of the couple of cents it costs you for your ISP access to download them.

The distribution version of Qmail supports the basic protocols such as SMTP and POP3, but the Qmail-LDAP patch adds a great deal of functionality including security features such as SHA, MD5, MD4, RIPE-MD160, SSL encryption, and support for OpenLDAP, Mozilla Directory SDK, and Novel NDS.

Users access e-mail through any POP3/SMTP-compliant client. Web access is not a standard feature, but is available as a third party plug-in.

Unlike Imail, it does not feature calendar functionality. Support for the product is a bit of a double-edged sword. On the one hand it is free, but searching for answers or sifting through replies from Linux gurus can be a bit confusing for the uninitiated.

To be fair, if you post a question and point out that you do not have an IQ above 160, most of the replies will be in a more down-to-earth and easy-to-follow format (if a little condescending).

On the other hand, commercial support can be found in quite a large number of consulting firms you can easily find on the Web. Of course the quality of service will depend on which provider you select.

Sendmail Version 8

The installation was effortless, and by default Sendmail is installed at the same time as the OS. Naturally, you still need to be Linux savvy to complete the configuration, but the installation is an automated process that just about anyone can handle.

Once installation and network configuration was complete, Sendmail required little tweaking--significantly less in fact than Qmail--to get it up and running.

Did we mention the cost of Sendmail? As with Qmail the cost is pretty much nil, as long as you don't need support. If you need support, this can be obtained from third-party companies at a cost. The same caveats regarding free user group and paid third-party support apply as with Qmail.

A commercial version of Sendmail is available from www.sendmail.com. This version not only includes a nicely presented box, documentation, and bundled support, but also features a GUI to help configure the package. Furthermore, the commercial version runs on Windows NT/2000, as well as the many flavours of Unix he free version runs on.

Configuring Sendmail is a long way shy of the simple point and click configuration of the Windows-based products, but it's somewhat easier than Qmail. You still need to know and understand quite an array of Linux commands and their parameters to complete the configuration.

The stock distibution version of Sendmail includes more bells and whistles than Qmail and seems to include most of the basic functionality needed to compete with the Windows applications.

There are even more third-party patches and plug-ins for Sendmail as there are for Qmail, and in general they are free as well. Naturally support for a few of the more esoteric patches may be less than satisfactory.

Because Sendmail is more feature-rich than Qmail, all things being equal it stands to reason that the program will be larger. And it is-1.74MB TARed (mind you this is still miniscule when compared to the Windows-based servers).

Protocol and security support are quite basic but can be easily enhanced with free third-party patches.

As Linux is inherently a network OS, it incorporates remote access as seamlessly as if you are physically on the console either via Telnet or more securely via SSH.

This is true of both Sendmail and Qmail, in fact any application that runs Linux. This provides excellent remote administration facilities to the operator. For example, if your company has a non-permanent or slow Internet link, you can co-locate your mail server at a remote site on a bigger pipe, and you would almost never have to physically visit the site.

Sendmail places all incoming users' e-mail into one easy-to-manage spool directory, unlike Q-Mail, which places mail into each individual user's home directory as default.

Although this technique can increase performance on very large installations (more than 10,000 users), the average corporate mail system would not benefit greatly and would be a lot harder to manage. It would be particularly troublesome as far as managing mailbox sizes, virus scanning, and backups are concerned.

The April 2002 issue of ZDNet Australia's Technology & Business Magazine contains reviews of mail server packages, including Editor's Choice Awards for the best products. For subscription information, visit Technology & Business.

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