Rule 2: Those who specify a mule, demand the same features as a mule, and have pre-determined that they want to buy it from a mule trader, will end up buying a mule!
Rule 3: If the objective was to buy the alternative to a mule that must be a mule, then the most likely outcome is that the objective will change as to accomodate the original mule.
So let's examine the specification:
a) You want an alternative to MS Exchange
b) You are addicted to MS Exchange (usage addiction is hard to overcome)
c) You want it to be free
Hmmm -- sorry, it does not stack up too well for choices.
So let's look a little deeper:
What is MS Exchange?
Answer: An integrated Message Transport Agent, Message Delivery Agent, Message Retrieval Agent, Message Routing Server, Calendar Synchronization and Resource Scheduling Tool, all tied inextricably to a Directory service database (Active Directory). This is a suite that is extremely tightly integrated to be deliberately near impossible to replace with exactly the same functionality.
There are no direct equivalents to MS Exchange, let alone totally free alternatives.
What can open source replace:
- Message Transport Agent:
sendmail, postfix, courier mail server, exim and many more
- Message Routing Server:
Same as above
- Message Delivery Agent:
lmail, rmail, deliver, mailman, courier mail server and more
- Message Retrieval Agent:
POP2/3, IMAP, Cyrus IMAP and a few lesser knowns
- Calendar Synchonization:
webcal, chronos, courier mail server
- Directory Server: openldap
When you weight it all up, the commercial alternatives look quite
attractive. They include:
SuSE OpenExhange Server -- see www.suse.com
Xchange XC -- see www.xchangenetwork.com
Do enjoy the choices!
- John T.
This was first published in May 2003