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Can you help me with my software licensing question?

How can we get the real information about the licensing on Microsoft product.

I try to get the number of mailbox i can create with a license of exchange, and il could not get the information anywhere.

I want buy this license, but no information about how many mailbox i can create with this license.

The question is what kind of licence i need to buy if i want a unlimited mailbox license ?

I got actually over 1200 mailbox, in mdeamon software, the mailbox number always grow ... so i need a licence for my scenario.

Someone can help me please ?

  • Provide some more details about your scenario and I am sure someone can help you out.
    – ITGuy24
    Feb 22, 2010 at 21:33
  • 1
    MS Licensing is intentionally opaque for end-users. Resellers have access to MS licensing specialists that end-users do not (unless you're a large corporate EU). The intention is to force end-users to work with resellers rather than do an end-run around them via the Internet or elsewhere. Having said that, as currently worded, this post is not a question. Please revise if you have a specific question otherwise this will likely be closed.
    – jamieb
    Feb 22, 2010 at 21:39
  • I have found the MS licensing so crowded as well.
    – twk
    Feb 22, 2010 at 21:40
  • @jamieb - I'm not too certain that's an accurate representation of anything, really. Feb 23, 2010 at 10:17

4 Answers 4


Exchange is not licensed by the mailbox (which is likely why it's difficult to find that number) Exchange is licensed by CAL. There are 2 types standard and enterprise. Enterprise is only required if you are doing Unified Messaging and advanced compliance. (not by the server type as mentioned in another post). MS Licensing is sometimes complicatied but every product has a licensing page (usually under How to buy). For Exchange see Exchange Server 2007 Licensing Frequently Asked Questions

  • or The Exchange Server 2010 Licensing FAQ microsoft.com/exchange/2010/en/us/Licensing.aspx
    – Rex
    Feb 22, 2010 at 21:53
  • Thanks for your link, but actually dont help me. I already read this page. Mailbox database, is not for each mailbox ? Feb 22, 2010 at 22:01
  • 1
    No, a mailbox database is not for each mailbox. The number of accounts you host in a single database is dependent on performance and the hardware you're going to be deploying on. I think you need to read up further on architecting and implementing Exchange. Databases have limitations on storage, and performance implications, depending on your number of users. How many users will you have on Day 1? What's your likely user count in 1 year, in 3 years?
    – mfinni
    Feb 22, 2010 at 22:07
  • Actually 1200 mailbox, in two year maybe 2500 - 3000 mailbox ... Feb 22, 2010 at 22:10

Ask your reseller? Ask Microsoft?

When you buy Exchange, it may or may not come with CALs, Client Access Licenses. The number of CALs you bought is probably directly related to the number of mailboxes you are licensed to create. There may be details relating to per-user or per-device, so you need to know what you bought and how your environment is configured. /Edit - someone posted the link to the '07 CAL rules, which was very helpful. There is no per-user or per-device (I think I was confusing it with Windows Server CALs) - it's just Standard or Enterprise. You just need 1 (probably standard) CAL per user.

  • I already try to contact microsoft, but it's really not easy to talk with somebody Feb 22, 2010 at 22:02

There really is no limit to the number of mailboxes you can create with any version of Exchange.

You buy the exchange license itself (Std/Enterprise) and you buy the Client Access Licenses (std/enterprise).

You do not need to buy an enterprise CAL if you buy the Enterprise edition of Exchange.. Likewise, you can buy an enterprise CAL if you buy the standard edition of Exchange.

Either way, it has no bearing on the number of mailboxes you can create.

But, yes.. Microsoft licensing can be fairly complicated and it is best to work with a VAR that has some specialist in licensing.

  • Technically, you can't create more than one mailbox per user. A mailbox is an AD attribute of the user object and as such, there's a one-to-one correlation between the two.
    – joeqwerty
    Feb 22, 2010 at 21:45
  • true, but you can create a resource mailbox and assign the user permission to the mailbox. The actual AD account can still be disabled and I do not believe counts against your CAL count.
    – Rex
    Feb 22, 2010 at 21:52
  • Yes, but that's still not creating two mailboxes for the same user. My comment isn't referring to CAL's or anything else, only your statement that you can create 10 (or some random number) of mailboxes per user, which you can't. No need to make things more confusing for the OP by giving him incorrect info. No offense intended.
    – joeqwerty
    Feb 22, 2010 at 21:56
  • True.. My wording is probably not very accurate. I'll correct :)
    – Rex
    Feb 22, 2010 at 21:57
  • So each user and each mailbox are a CAL licence ... ??? Feb 22, 2010 at 22:04

Microsoft licensing can be complex but knowing where to find the actual licence terms is the first step in understanding the rules you need to comply with.

The licence terms which apply to the software you have purchased depend on how you purchased the software.

If you acquired the licence as a Full Packaged Product (FPP), which is essentially retail boxed product, then a document known as the Microsoft Software Licence Terms (MSLT), formerly known as the an End User Licence Agreement (EULA) will apply. Those licence terms appear as part of the installation process but in many cases they can also be viewed and downloaded from the following Microsoft website:


Each product, each Version of a product and in some cases each Edition will each have its own MSLT which contain its own product specific licence terms.

If you acquired the licence as an Original Equipment Manufacturer (OEM) licence, then the licence terms are likley to be different from the FPP licence terms but once again they can be accessed at the same URL as above.

If you have acquired the software licence through a Microsoft Volume Licence Agreement (which is typically the case for most organisations then the licence terms which apply to your usage are found in a document called the Product Use Rights (referred to as the PUR). The Product Use rights contains the licence terms for all Microsoft software available through Microsoft Volume Licensing. A new version of the Product Use Rights is released every 3 months as a general rule. That document, and archived copies of previous versions can be accessed from the following Microsoft URL:


You will also see another document available on this same URL called the Product List which contains other relevant licensing information.

So together with the actual Volume Licence Agreement contract itself, these two documents contain all the actual licence terms and conditions that your organisation will need to adhere to. But as I have pointed out above, these terms ONLY apply to software licenses acquired through a Microsoft Volume Licence Agreement. For FPP and OEM licenses, you will need to refer to the relevant MSLT or EULA document.

In answer to your question about Exchange Server:

Exchange Server, like many other Microsoft Server products (but not all) is licensed under the Server + CAL licensing model. In basic terms, a Server licence is required to install the Server software itself and then a Client Access Licence (CAL) is required for each User or Device that accesses the software (directly or indirectly).

Without going into too much detail, each device or each user which accesses the Exchange Server requires a CAL. You can assign each user a User CAL, or each device a Device CAL, or a combination of the two. A device which has a Device CAL assigned to it can be used to access the Exchange Server Software by any User. A user who has a User CAL assigned to them can access the Exchange Server software from any device.

From a licensing perspective it does not matter how many mailboxes the Exchange Server has. i.e. You can setup as many mailboxes as you like however any User or Device which is accessing those mailboxes will need a CAL.

As an example:

If you have a company with 5 users but need 100 mailboxes, then you will need 5 User CALs (or you can alternatively acquire CALs for the devices they use) as you only have 5 users who are accessing the Exchange Server sofwtare.

If you have a company with 5 mailboxes, but which are shared by 100 employees, then you will need 100 User CALs (or alternatively you could acquire Device CALs for the devices they are using) as you have 100 users who are accessing the Exchange Server software.

If you need any further clarification let me know. I hope that all helps!

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