Business
Seven mail servers tested
Exchange might be the most popular but is it the best? We test the alternatives.
While I have dabbled with various different Linux- and Windows-based mail systems over the years such as Postfix, Exchange, Domino, and Q-Mail, I keep returning to Sendmail.
The choice for Sendmail and other variants of Linux-based mail servers is fairly obvious -- the operating system. Linux is a very robust operating system to use when facing the public Internet and when running critical online applications.
Particularly so in the days before alternative means of Internet protection such as firewalls, intrusion detection or prevention systems (IDS/IPS).
Linux also has phenomenal reliability and can work with limited resources, we have an Intel PII 233MHZ CPU/128MB RAM server running Slackware/Sendmail which has been running with approx 500 mailboxes for the last six years with just one failure (a PSU fan). It has only been administratively down three times in that period, twice for routine maintenance to replace/upgrade the hard disk drive unit and once to relocate it to a different datacentre.
Don't worry this will not be a pro-Linux rant, we can assure you that we are certainly not a supporters of any one particular platform, operating system or appliance.
Remaining independent and subjective one has to concede that some features not readily enabled in a Linux environment would be seen as attractive to enterprise level IT departments, engineers, and technical staff.
These features are things such as:
- Ease of management and administration (particularly patch and security).
- Wide availability of vendor support and training
- Access to a ready stream of certified, experienced engineers
It also provides easily deployable integrated application options such as:
- Instant messaging (IM)
- Compatibility with advanced e-mail client application/features
- Unified Directory services
- Collaboration services
- Global document management
- Global calendar/diary functionality
- Global personal information management systems (PIM)
- Customer relationship management systems (CRM)
- Journaling or time logging capabilities
- Support for emerging devices and applications such as Blackberries, VoIP and other global system services
As mentioned, while some of these are available as additional applications and plug-ins to various flavours of Linux and its associated mail servers they are not as readily accessible or unified as most of the "other" vendors packages.
Malicious content
The majority of virus and malicious content such as worms are still spread these days via the Internet e-mail system, therefore it would be advisable to evaluate and deploy a separate dedicated e-mail antivirus application, for more information see the review I performed in the April 2004 edition of T&B "Stop MyDoom being your doom".
Spam, spam, spam, glorious spam
Another e-mail borne nuisance is spam, this requires a fair bit more planning and evaluation once you have settled on a mail server platform you can start down that path. For more information see the three reviews we have performed in the past for T&B in the July 2003, October 2003, and December 2004 editions.
E-mail security gateways and services
Due to the fact that in some way, shape, or form e-mail servers need to be publicly accessible and online 24x7x365 then a definite consideration when looking at your e-mail systems security would be to consider a gateway device. Two that we have come across in the past are Ironport who provide robust network attached security appliances which process the network traffic prior to delivery and after messages have been sent. For a complete managed e-mail security solution in a similar vein then see the folks at Network Box they deliver, configure and remotely maintain and monitor an e-mail gateway server at your own premises.
Harden the servers O/S and batten down the perimeter
Next on the list is to ensure that the server's operating systems are correctly hardened, primarily by turning off or disabling all services, processes and ports that are running unnecessarily. Also it would be assumed that the network perimeter security is correctly setup and fire-walled, (see our firewall review in the March 2004 edition of T&B), to allow a certain level of port access, preferably with an adequate multi-homed firewall, not just a default de-militarised zone (DMZ).
Avoid the common mis-configuration traps
There are a couple of configuration items that some engineers commonly overlook or misconfigure when setting up an e-mail server. Mail servers must never be allowed to run open relays and ensure the domain name servers are correctly configured for reverse IP address lookups as well as forward name lookups.
Don't be a relay point for spammers
Firstly get your relaying correct, identify the public and private domains that the mail server will be responsible for handling and make sure that those and only those machines on those networks are explicitly allowed to relay e-mail even to the point of using individual IP addresses on your subnets in the configuration files. If relaying is not correctly setup then those with nefarious intentions, generally spammers, could discover the open-relay server and start using that mail server as the launching point for their spamming activities, this generally would result in that mail servers IP address being added to a registered black list (RBL) service and therefore subscribers to that service would no longer receive messages from that mail server even if they were legitimate. Not a good look if you are a high profile organisation. Plus it can sometimes be quite difficult and time consuming to discover which RBL your mail servers IP address has been added to and then have it removed.
Ensure name servers can resolve forwards as well as back
To ensure those with designs on taking over a domain name for their own purposes don't get their hands on it one must ensure that the company domain name servers are correctly configured to not only resolve from domain name to IP address but also reverse lookups from IP address to domain name. It is also critical to ensure that the secondary name server (which automatically updates its name databases from the primary server) is setup to only accept update data explicitly from the primary servers IP address this stops those with nefarious intentions from uploading a changed zone file to the secondary server and then crashing the primary server causing the secondary server to start feeding out the unauthorised server IP information for that domain name.
The first cab off the rank is IBM with Domino Server 6.5.3. And with an array of access and administration options it is hard to know where to begin.
Firstly, one needs the actual Domino server installed, this in itself is not much to look at, just a console window with text-based status information and events in it. To administer, monitor, and configure this there are two options, the first is Domino Administrator which is a separate standalone application which interfaces with the Domino server.
The second option for administration, and technically more portable as it is Web based, is the browser admininistration interface. Both these administration interfaces are surprisingly similar and give the user full access to the overwhelming myriad of configuration options available.
While first impressions can be quite daunting it only took me about half an hour or so to be quite proficient in accessing and configuring the various settings.
Users accessing their e-mails have three Lotus specific interfaces to choose from as well as traditional e-mail clients. Although with many specific features available most deployments of Domino would be matched with a Lotus client. The three Lotus e-mail clients are, Lotus Notes, Domino Web Access, and Webmail.
Lotus Notes is a standalone e-mail client residing on the users desktop. Domino Web Access is accessed via a Web browser and is a rich browser client using dynamic HTML (DHTML) and Extensible Markup Language (XML), Webmail is a lightweight HTML client also accessed via a Web browser and is far simpler.
All in all, Lotus has put together a very configurable and customisable mail system with many options available to allow clients and systems integrators to tailor the system to the enterprises needs. If you are after a large-scale mail server then add Domino to your shortlist for evaluation.
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Ipswitch sent us a really neat package called the Ipswitch Collaboration Suite premium edition which not only contains the iMail Server but e-mail and discussion lists, secure instant messaging, schedule and contact sharing, anti-spam filters, and antivirus protection.
We were only interested in the iMail Server for the purposes of this review. Installation could not have been easier, likewise the initial configuration. This package really is simple, unfortunately too simple. Perhaps a few years ago a mail server like this would have been quite good, however when compared to any of the other packages in this review the Ipswitch iMail Server lacks in many areas.
We decided not to can the product immediately but to press on and have a look at its Web messaging interface and Web calendaring. Unfortunately this was equally unimpressive, quite awkward and very basic. It may well have just been the design and layout but it seemed to lack the finish, features, and polish of all the other applications.
In summary perhaps iMail was a good server in the past, but it has seen its day and definitely is due for some graphical and feature overhauls. On the upside, at least not all of Ipswitch's products are like this, I can personally attest to the fact that its popular WSFTP and What's Up applications are both excellent products.
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Kerio has a very impressive product with MailServer 6, that is easy to install, configure, monitor, and administer. This application comes in two parts, the first part is the mail-server engine itself and the second is the administration application.
It took us less than five minutes to install and configure this mail-server. Mind you it took about half an hour to play around with all the options and features in the administration console. One of the best features of this application is its comprehensive in-built anti-spam engine, which is based on Spam-Assassin.
As you can see from the screenshot the package is well featured without being overly complex and the finish to the product is exemplary.
If you are after a small to medium enterprise solution that is ridiculously easy to administer then you would be hard pressed to go past Kerio MailServer 6 -- I suggest you download and begin evaluating it today.
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Microsoft Exchange is probably the most commonly used mail server in enterprises. We would've used Exchange servers on an almost daily basis over the last 12 months in test rigs for various projects. Exchange 2003 builds incrementally on the previous version, and has a greatly improved mobile device support list.
The Exchange application configuration, management and monitoring is via a management console. This console is very straight forward to navigate and administrators can quickly find the particular options they are looking for. More monitoring tools would be a nice addition in the future, particularly real time tools.
While Microsoft have placed an ever growing emphasis on information technology security over the last 12 months. To really reap the benefits of true security without having to spend hour upon hour tweaking, disabling, and reconfiguring processes, services, and applications it is best to begin migrating to Microsoft Windows Server 2003 at the same time as making the move to Microsoft Exchange Server 2003 -- this is not to say you can relax your guard as there are still a few advisable security tweaks and precautions one needs to take care of but they are just a lot less and a lot more straightforward.
Microsoft has finally realised it is not worthwhile trying to ship a product that tries to be everything to everyone with all bells and whistles running and open from the initial install, instead it leaves it up to the owner to install and start only the components they need the machine to handle... mostly.
Overall, a wise step forward for Microsoft and slightly better to manage and maintain mail server than previous incarnations. Added mobile device and remote mail support may be advantages to some enterprises.
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The last time we really had anything to do with Novell, apart from using it functionally as the University's e-mail system, was back in the dim dark days of 3.1 and 4.01. Things have certainly changed a fair bit since then.
Installation was straightforward, the Novell engineers who assisted the Lab with the installation suggested a large enterprise install and configure would take between five to eight hours. Management is excellent mostly being achieved remotely by Novell's centralised management tool called ConsoleOne. ConsoleOne can administer several Novell servers from the one administrative workstation.
For those interested in the behind the scenes nuts-and-bolts there is still a purely text-based interface on the server which mostly allows engineers to monitor activity and log events. It is always good to know that when the GUI stops responding there is still a CLI to turn to before panicking. As one would expect, Novell uses its directory service for the majority of the user and group control.
Groupwise should easily scale up to 30,000 or even 40,000 users. An interesting feature is Novell's quickfinder technology which integrates a document management indexing and search facility into the users interface that is updated periodically (default is once every 20 hours) that allows authorised users to search through global or group document stores for keywords.
Overall a powerful package with perhaps not so many customisable options as Domino, but still worthy of evaluation if a large-scale mail server deployment is on the cards.
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A must when contemplating a Sendmail environment is to purchase a copy of the O'Reilly -Bat" book (Building, Installing, and Administering Sendmail by Bryan Costales with Eric Allman) -- this is a comprehensive guide to pretty much anything one needs to know about Sendmail and is extremely easy to follow.
One thing that Sendmail has never been known for is its ease of configuration (particularly the virtually cryptographic Sendmail.cf file), while it is simple to get up and running fine tuning and tweaking it can leave one a little wobbly in the knees let alone in the head. Don't worry if you need help or extra features and are willing to pay for them, the developers of the freeware version of Sendmail have a commercial company, see www.sendmail.com.
A myriad of open-source plug-in applications are available for managing and monitoring Sendmail. A very popular tool for those with a GUI bend on Linux is Webmin. I ran up a server with Slackware 10.0, Sendmail and installed Webmin for the purposes of this review. Webmin not only manages Sendmail but also many other aspects of Linux applications and their associated configuration. And the best bit is the author of Webmin comes from Melbourne. Ok so it is a bit of a soft option for most hardcore Linux nuts out there who prefer the CLI but some people must eventually grow up and realise not everyone is a ubergeek super programmer who live, eat and breath in vi commands. In that vein if you are looking for a laugh then check out www.ubergeek.tv.
It is a very reliable, robust, scalable solution when combined with Webmin, and a decent Linux distribution should give the owner many years of faithful service. If you haven't tried it, get the book and give it a spin in a test environment -- you should be pleasantly surprised.
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If a company has a requirement for a basic, easy-to-administer mailserver, then OpenExchange Server 4 must be on the shortlist for evaluation.
And before the Microsoft proponents out there start jumping up and down about us recommending Linux and its lack of formal support and how it has been mashed together by a rogue bunch of anarchistic hackers so it may not be around tomorrow, SuSE was bought last year by Novell.
So there should be plenty of support and future for this product, now it is the Linux community who can start ranting and raving about the coming of the end of the world through the commercialisation of some Linux distributions.
Installation and full configuration takes less than a couple of hours. Management is easily completed via a well-featured interface accessible through any Web browser. The underlying mail server used is called Postfix. In the basic, and even advanced, graphical configuration windows OpenExchange misses some more obscure and complex configuration options, however for all the diehards there is a page for manually changing the main.cf and master.cf postfix config files.
The menu system is well setup allowing for easy management of users and groups. Of particular note on the monitoring side of things is administrative access to a very impressive range of round robin database tool (RRDtool) graphs. For those familiar with multi router traffic grapher (MRTG) you will be familiar with the type of output Tobi Oetiker's applications produce. In the OpenExchange monitoring system RRDtool is used to show.
- System overview (CPU usage, system load, memory usage, processes, and swap-file)
- Disk I/O (I/O rates)
- Partitions (Free space)
- Network traffic (I/O etc)
If you are in the market for a basic mail server that is easy to use and monitor, then definitely look at Novell's SuSE Linux OpenExchange Server 4.
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| Product | Domino | Ipswitch Collaboration Suite | Kerio MailServer |
| Company | IBM | Ipswitch | Kerio Technologies |
| Web site | www.lotus.com | www.ipswitch.com | www.kerio.com |
| Phone | 13 24 26 | 1 781 676 5700 (US) | 1 408 496 4500 (US) |
| Price | AU$51.22 to AU$65.70 ex GST per user. Scenario 1 (200 users) AU$13,140 ex GST, Scenario 2 (30,000+ users) AU$1,544,000 ex GST. | Starting at US$1495 | US$449 (20-user license) |
| Warranty | 12 months software maintenance is included in price which covers support and upgrades | 60 days | N/A |
| E-mail support (times/cost) | N/A | One-year's support included in price | Unlimited with subscription |
| Phone support (times/cost) | N/A | One-year's support included in price | Unlimited with subscription |
| Other support information | N/A | One-year's support included in price | Forum, partner support |
| CPU (min/recommended) | Microsoft Windows: Intel Pentium or higher; Unix: Power PC, Intel Pentium, UltraSPARC; iSeries: Power PC; zSeries: any CPU that supports the O/S release level; zO/S: any CPU that supports the O/S release level | Pentium 350 MHz | Microsoft Windows: CPU 500 MHz, Red Hat Linux: Pentium 500 MHz, SUSE Linux: Pentium 500 MHz, Apple Mac OS X: G4 or G5. |
| Memory (min/recommended) | Microsoft Windows: 512MB, Unix: 512MB, iSeries: 512MB, zSeries: 1.0GB, zO/S: 1.0GB | 64MB RAM | 256MB RAM |
| HDD (min) | Microsoft Windows: 1.5GB, Unix: 1.5GB, iSeries: 2.0GB, zSeries: 2.5GB, zO/S: 3 Volumes | 10MB | MailServer application (not including mail store) 35MB |
| Network requirements | Microsoft Windows: TCP/IP, Netbios, NetBEUI, X.PC; Unix: TCP/IP, X/.PC; iSeries: TCP/IP; zSeries: TCP/IP; zO/S: TCP/IP | TCP/IP connection | TCP/IP and Internet connection |
| Other hardware recommended/required | N/A | N/A | N/A |
| Operating system | Windows 2000 / 2003 Server, AIX 5.2, Linux (Novell SLES 8), Solaris 9, OS/400, i5/OS, z/OS | Windows | Windows 2000/XP/2003, Red Hat 9.0, Red Hat Enterprise Linux 3, Fedora Core, SUSE Linux, Pentium 500 MHz, 256 MB RAM, SUSE Linux 9.0, Mac OS X 10.2 Jaguar, Mac OS X 10.3 Panther |
| Other software recommended/required | N/A | N/A | Groupware clients Microsoft Outlook 2000/XP (Windows 2000/XP), Microsoft Entourage X/2004 (Mac OS X 10.2 & 10.3) WebMail clients Microsoft Internet Explorer 6 and higher, Mozilla 1.4 and higher, Apple Safari 1.2 and higher |
| Product | Microsoft Exchange Server 2003 Enterprise Edition | Novell GroupWise | Novell Open Exchange |
| Company | Microsoft Australia | Novell | Novell |
| Web site | www.microsoft.com | www.novell.com | www.novell.com |
| Phone | 13 20 58 | 03 9520 3500 | 03 9520 3500 |
| Price | AU$12,181 incl GST (25 clients) | Approx AU$160 per user per 12 months (basic pricing) | AU$1715 for server and first 10 clients for 12 months -- extra client starting from AU$65 /12 months |
| Warranty | N/A | 90 days from date of purchase | 90 days from the date of purchase |
| E-mail support (times/cost) | 24 hours/no cost -- response time is 1 business day | Included in premium support contract | Included in premium support contract |
| Phone support (times/cost) | 9am-5pm (Pacific Time)/AU$297 per support issue | From AU$630/incident to AU$6500 premium support | From AU$630/incident to AU$6500 premium support |
| Other support information | Customers can sign up for a premier support service that includes all Microsoft products. | Full 24x7 worldwide coverage available. | Full 24x7 worldwide coverage available. |
| CPU (min/recommended) | Intel Pentium or compatible 133MHz or higher processor/Intel Pentium or compatible 550MHz processor | Server class Pentium III or equivalent | Min Pentium III & AMD Athlon/Duron |
| Memory (min/recommended) | 256MB/512MB or more | 512MB | 256MB/512MB |
| HDD (min) | Need: 500MB on the hard disk where you install Exchange Server 2003, 200MB on the system drive, and additional disk space for mail storage. | 2G | 9G/15G RAID |
| Network requirements | Network connection required 10Mb or above | TCP/IP, supports RIM Blackberry, Palm, and Windows CE devices | TCP/IP |
| Other hardware recommended/required | CD drive | Can be clustered for scaling and high availability | N/A |
| Operating system | Microsoft Windows 2000 Server, Windows 2000 Advanced Server, or Windows 2000 Datacenter Server with SP3 or later Windows Server 2003, Standard Edition; Windows Server 2003, Enterprise Edition; or Windows Server 2003, Datacenter Edition | NetWare, Linux, Windows | SuSE Linux Enterprise Server 8 -- included |
| Other software recommended/required | N/A | Client software for Windows and Linux | N/A |
This company has 200 users but is looking to expand to 400+ in the next few years.
Approximate budget: Small
Requires: A mail server that can cope with the company's intended growth.
Concerns: Cost -- the mail server needs to be inexpensive and easy to maintain.
The Scenario 1 winner is Novell's SuSE Linux based OpenExchange, closely followed by Sendmail. Novell's application is far easier to manage, but also costs $$$.
Sample scenario 2
This large company has 30,000 staff spread across five geographic locations and requires a mail server.
Approximate budget: Open.
Requires: A mail server that is powerful and secure. Remote administration and Web access for travelling staff is a must.
Concerns: Cost isn't an issue, but reliability is very important.
The Scenario 2 winner is IBM Domino for its scalability, support, and mobile options. It also helped that cost wasn't an issue for the scenario company.
There are three Editor's Choice winners this month, each covering a very specific category.
For those looking for a robust, powerful, and reliable mail system with limited bells and whistles then Sendmail is the winner. For those SMEs needing a simple-to-install and manageable e-mail server system with good support then Novell OpenExchange Server 4 is the winner with Kerio MailServer 6 coming a close second.
And for those needing a server with the majority of bells and whistles covered then it is a closely run race between IBM and Microsoft with Microsoft just pipping IBM at the post.
This article was first published in Technology & Business magazine.
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