Mail Servers

A server is a computer or a device on a network that supplies information in many forms to other computers as well as servers on the network. Servers can be Hardware or Software of both. Some examples of common servers are Web servers, proxy servers, mail servers, file servers etc. Mail Servers are your virtual Post Offices that handle your incoming and outgoing e-mail. E-mail already being the dominant method of communication worldwide with hundreds of millions of messages sent across the Internet daily, Mail Servers can be regarded as a critical pillar of any organization as a downtime of even a few minutes can cause huge losses. If Information is the Key, then Mail Servers are the key chains that keep you firmly in touch with information.

There are many flavors of email servers out there. On different platforms, Open Source as well as proprietary, Free as well as paid.

A brief overview of some of the popular mail servers in use today.

Microsoft Exchange server:

is a mail server product from the Dominant Software Company, Microsoft Corporation. It not only handles mails but also other provides for a Messaging and Collaboration server. It works in conjunction with mail clients such as Microsoft Outlook, Outlook Express, and other email clients. As it is a paid service, quick deployment and a host of support tools makes the Exchange server easy to manage.

Pros: Easy to manage and support from company available.

Cons: Platform Dependent and tied to the Windows platform makes it more prone to hacker attacks and viruses.

IBM Lotus Notes/Domino:

is the competing paid product from the IBM Stable. It too is feature rich and the pedigree ensures a high level of support.

While Microsoft Exchange will only work on the Microsoft Operating systems, IBM Lotus notes will work on a variety of platforms including Windows. Red Hat Enterprise Linux, SuSe Linux Enterprise Server, Solaris, AIX, z/OS, and other Linux flavors.

This gives decision makers greater flexibility in determining their other software needs.

Pros: Comprehensive set of features such as messaging, emailing, collaboration. Works on a variety of platforms.

However, the Giant share of mail servers worldwide is not with Microsoft nor IBM, the two King Kongs of the software world.

That distinction goes to Open source mail servers such as Qmail, Sendmail, Postfix.

But being open source does not necessarily mean that these products are not reliable or support is sketchy. It's adoption by some of the biggest names on the Internet speaks volumes of its reliability. In addition, while the software is essentially “free”, commercial support is available from many organizations and companies. In addition, the community support for open source mail servers or MTAs as they are popularly known (Mail Transfer Agents) is excellent and very comprehensive.

Sendmail:

Almost synonymous with MTAs, Sendmail is one of the earliest MTAs that was derived from the delivermail program developed at UC-Berkeley. By early Nineties, as a result of the widespread deployment of Unix systems, in network server environments, sendmail became the de-facto MTA.

With availability of various other “better” MTAs the usage of Sendmail is on the decline but even conservative estimates still give it a Lion's share of the market.

Pros: Widespread support, Freeware version is under active development and is very powerful and configurable.

Cons: Freeware version is complex to configure and a frequent target of hackers being the most ubiquitous MTA.

Qmail:

Sometimes called the second most popular MTA and sometimes called the replacement for Sendmail, Qmail is a bit of both and much more.

Developed by by Dan Bernstein in an attempt to overcome the security vulnerabilities of Sendmail, Qmail runs on almost any *nix system.

Pros: Extremely reliable and stable with paid and free versions available. Fast and secure too. Modular.

Cons: Fewer Features, Not backward compatible with existing sendmail setup.

Postfix:

One of the newer MTAs on the block now, Postfix is reputed to be safer, faster and easier to administer than Qmail. However it was developed as a drop in replacement for sendmail. Postfix works on almost all flavors of *nix and is fast gaining popularity.

Pros: Modular Design, Secure, use of smaller daemons resulting in better performance. compatibility and easy configuration.