https://support.eset.com/kb2404

1. What is ESET Mail Security for Microsoft Exchange Server?
   ESET Mail Security for Microsoft Exchange Server (EMSX) integrates server-side antispam features and protects both the Exchange mailboxes and the host server environment from malware attacks. For more information on ESET Mail Security, visit the following product page: ESET Mail Security for Microsoft Exchange Server.
   
   Known issues
    
2. What are the key new features and benefits of ESET Mail Security 6 for Microsoft Exchange Server?
   
   See the following Knowledgebase article for a full list of new features in EMSX 6: What's new in EMSX 6?

3. Is there a change in pricing between earlier versions and ESET Mail Security 6 for Microsoft Exchange Server?
   There is no change in pricing.
    
4. How do I upgrade from an earlier version to ESET Mail Security Microsoft Exchange Server and is there an upgrade fee?
   An existing customer of an earlier version of EMSX will be able to upgrade to the latest EMSX for free. Please see the following Knowledgebase article for step-by-step upgrade instructions:
   
   How do I upgrade ESET Mail Security for Microsoft Exchange Server to the latest version?
    
5. Can I install on Microsoft Exchange Server 2013?
   Yes. However, you must install ESET Mail Security on a system running Microsoft Exchange 2013 with Mailbox server role. Client Access server role is not supported by ESET Mail Security.
    
6. Will an ESET Mail Security 6 for Microsoft Exchange Server license work with an earlier version?
   Yes, the new license is backwards compatible. However, EMSX 6 is activated with a License Key, whereas earlier versions (version 4.5 and earlier) require an ESET-issued Username and Password during activation. Your License Key, Username, and Password were sent to you after purchasing your product. If you need your license information resent, click here.
    
7. How many licenses has ESET Mail Security for Microsoft Exchange Server used?
   In order to determine the number of licenses that have been used by ESET Mail Security for Microsoft Exchange server, please see the following Knowledgebase article: How does ESET Mail Security 6 for Microsoft Exchange Server count mailboxes?
    
8. I installed ESET Mail Security for Microsoft Exchange Server and my antispam module will not activate
   You must request a new license file. Visit the Lost License page and enter your product username, or your email address that was used to purchase the license. You may also contact your ESET representative.
    
9. What operating systems are supported?
   EMSX supports Microsoft Windows 2000 Server
   Microsoft Windows Server 2003 (x86 and x64), 2008 (x86 and x64), 2008 R2, 2012, 2016
   Microsoft Windows Small Business Server 2003, 2003 R2, 2008, 2011
    
10. What versions of Microsoft Exchange Server are supported?
    This product supports the same versions of Microsoft Exchange as its predecessor, plus later versions:
    • Microsoft Exchange Server 2000 SP1, SP2, SP3 (32-bit version)
    • Microsoft Exchange Server 2003 SP1, SP2 (32-bit version)
    • Microsoft Exchange Server 2007 SP1, SP2, SP3 (64-bit version)
    • Microsoft Exchange Server 2010 SP1, SP2, SP3
    • Microsoft Exchange Server 2013
    • Microsoft Exchange Server 2016
       
11. I am running two Exchange Servers, one primary server with transport roles and a secondary server as a mail store. Do I need EMSX installed on both?
    Yes. In general, it is recommended to install EMSX if there is an Exchange Server running on the machine.
    
    EMSX offers two types of protection, one on Transport Layer (Server 1 with “transport role”) and one on database level (Server 2 based on VSAPI). On VSAPI, only antivirus protection is offered. The advantage of this functionality is that email messages stored on the mailbox server are always scanned with the newest antivirus database “on read”, and also periodically, if background scanning is enabled. On the first server, they are scanned only “upon arrival” (this is where antispam takes place).

    With our licensing, users purchase protection for a certain number of mailboxes, and you are able to install it on all servers within your site (both Mailbox/Edge/Hub).

12. Is ESET Mail Security for Microsoft Exchange Server available in multiple languages?
    Localized builds are available from the "Select language" drop-down menu on the EMSX Download page.
     
13. Is there an in-product quarantine for spam in ESET Mail Security for Microsoft Exchange Server?
    Yes. EMSX 6 now features a local Quarantine management interface. Click here for more information.