Official Avaya documentation for Avaya IX™ Messaging release 10.8 specifies that the customer is responsible for providing and licensing the required Microsoft Windows Server operating system; it is not included in the software bundle. The documentation also explicitly recommends that the software be installed on dedicated servers for performance and stability. For high-availability configurations involving multiple servers, there is a critical warning that logging into any server before the initial database synchronization has finished will cause database corruption, which prevents all subsequent logins on all servers in the configuration.

A. The customer must supply the Microsoft Windows operating system. Avaya does not provide it with the IX™ Messaging software.

E. Avaya best practices and official documentation state that Avaya IX™ Messaging should be installed on dedicated, not shared, servers.

1. Avaya IX™ Messaging, Release 10.8, Installing and Upgrading Avaya IX™ Messaging, Document Number: 16-604203, Issue 5, December 2019.

For Answer C: Page 15, Section "Server requirements", lists the supported Windows Server operating systems that must be installed by the customer before installing Avaya IX™ Messaging. This confirms the OS is not provided.

For Answer B: Page 15, Section "Server requirements", states, "Avaya Messaging should be installed on dedicated servers specifically intended for the purpose."

For Answer D: Page 101, Chapter "Installing the secondary server", contains the following warning: "Important: Do not log in to the servers before the synch is complete. Logging in before the synch is complete will corrupt the database, and prevent all logins on all servers."

2. Avaya IX™ Messaging, Release 10.8.1, Overview and Specification, Document Number: NN43100-107, Issue 1.0, November 2019.

For Answer B: Page 10, Section "Server Requirements", explicitly states: "Avaya Messaging should be installed on dedicated servers specifically intended for the purpose."

For Answer C: Page 10, Section "Server Requirements", details the supported operating systems (e.g., Windows Server 2016 Standard/Datacenter), which are prerequisites for installation, implying they are customer-supplied.