SquirrelMail is licensed under the GPL. The cost to you can be explained with this short list:
* Licenses are $0 per license when purchased in small quantities (1-50)
* Bulk licenses are $0 each (51-500)
* If you need more licenses we can work out custom pricing.
* Site licenses are available for $0, many people choose this option for bang-for-the-buck.
* Support is available on the SquirrelMail mailing list at a rate of $0 per incident. (see [support])
* Each license comes with a source code license and a redistribution license.
* Users wishing to license in currencies other than the American Dollar can assume a 1:1 conversion rate.
* Prices are without VAT.
I still don't get it ...
SquirrelMail is a Free Software and an Open Source program. Many people are not familiar or used to this concept, you should, at a minimum, read the GPL. It cannot be overemphasized, SquirrelMail is FREE! It is free both in the financial sense (that is, its price is $0) and the sense of liberty (as in we do not attempt to limit your rights to use, improve, learn from, share, or even sell the software).
Why do you do this?
The SquirrelMail developers have many motivations. It is not, however a commercial entity, and we do not collectively offer any paid services.
What about support?
SquirrelMail is designed with the Unix admin in mind. It is simple to install and easy to administer. Many people on the mailing list offer help to new SquirrelMail users gratis. (Webster:gratis -- it's Latin :-) (see [support] for whom to contact.)
If you need more direct, immediate, or personalized support someone on the list may be willing to act as an independent consultant.
If you want to retain someone in this capacity, it is important to be as specific as possible about what you need. Remember, there are users from all over the world on the list.
If your needs aren't met on the list, you ought to check with local consultants and Professional Services companies.
For more information:
* http://www.gnu.org/copyleft/gpl.html -- A complete description of your legal rights and responsibilities
* The COPYING file that came with your SquirrelMail installation
* http://www.fsf.org/ -- Free Software
* http://www.opensource.org/ -- Open Source
Keep in mind:
You obtain permission to modify and/or distribute SquirrelMail by agreeing to the terms of the GPL, and may not otherwise, so you should make yourself familiar with it.
If you make changes that are of general use, please contribute them back. We're usually really receptive to patches that others can use..