posted by Alex Chejlyk on Mon 18th Jul 2005 17:09 UTC
IconMicrosoft dropped support for Exchange 5.5 on December 31st, 2004. Exchange 5.5 users can upgrade to Exchange Server 2003, continue to run 5.5 with all accompanied security risks, or switch over to another mail/groupware system.In this article I propose a fourth option that is really options two (run Exchange) and three (run another mail system) combined.

Exchange 5.5 is no longer supported by Microsoft as of December 31, 2004. According to Microsoft, organizations have two options. The first is to upgrade to Microsoft Exchange Server 2003, this is what Microsoft wants you to do. This means purchasing new hardware, new licenses and learning a totally different operating system (Active Directory, anyone?) and being tied into Microsoft once again.

The second option is to continue running Microsoft Exchange 5.5 and hope no one finds a new exploit. Microsoft frowns on option number 2, and I have to agree, Exchange 5.5 is not secure enough to serve Internet mail, especially without Microsoft patching it.

There is a third option that isn't mentioned by Microsoft. Change over to another mail/groupware system. This is a valid alternative if you have the time and resources. The worst part of changing to a new system is getting the email clients to behave, and getting the users of said email clients up to speed.

In this article I propose a fourth option that is really options two (run Exchange) and three (run another mail system) combined. The downside of options two and three will be mitigated while the functionality remains the same. The cost of all this? Depending on the amount of users, it starts at $200USD, and about a weekend's worth of time. The time varies greatly upon the level of expertise and the amount of users.

What we will be doing is running NT4/Exchange inside the Linux OS via a virtual machine, VMWare is the vm recommend for its ease of use and stability. We will use a more secure MTA, such as Postfix and we will receive mail via an Imap server, such as Cyrus. Exchange 5.5 will not connect to the Internet at all, and all mail will be filtered through the more secure systems before Exchange has to deal with it. We can even have Exchange 5.5 forgo all mail handling, and only perform address book and calendar sharing.

What you will need:

  • A virtual machine package that can run Windows NT Server (VMWare Workstation for Linux is what I use);
  • A decent server (A PIII 1Ghz minimum with ample HD storage and 512~1Gb Ram);
  • A working knowledge (plus packages) of Linux, Postfix and Cyrus (I recommend Kolab2 on top of Debian);
  • A licensed copy of Microsoft NT 4 Server and Exchange 5.5 Server with CALs (If you don't have a legal copy, check the Internet, it is inexpensive now);
  • A working knowledge of NT4/Exchange 5.5 (If you've installed and run it before, then you should have the knowledge).
  • The information contained in this article is rather superficial. This isn't an in-depth how-to, but rather a pointer as to how it can be done. A good tech will be able to take this information and implement it using the knowledge that he or she already possesses.

    Backup your current NT environment, including Exchange. I've only done smaller networks with less than 40 users, so I relied upon making a pst of everyone's mailbox and creating an additional pst for public folders. There are several methods to backup an Exchange system, do what is most comfortable.

    Install your Linux OS, VMware and your Open Source mail system. I use and recommend Kolab2, it is a mail and groupware system that performs the same duties as Exchange, plus the added benefit of spam and virus filtering. If you choose Kolab2 you also have a migration path away from Microsoft and Exchange, which you may or may not choose to implement.

    Create your user accounts in the mail system. There is no script that will create users for both Exchange and Unix accounts that I know of, but you can write one utilizing a macro program, Perl and/or Bash.

    Inside VMware, install NT4 and Exchange 5.5. Import all user accounts, or re-create accounts whichever uses less time. Block all Internet access from the NT4 virtual machine.

    Table of contents
    1. "Exchange & Linux, page 1/2"
    2. "Exchange & Linux, page 2/2"
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