When installing the Mailbox server role you are given the option to disable malware protection.
If you disable it now you can enable it again later. If this is the not the first server you’re installing and there is no Send Connector defined for outbound email then you may see a warning, but you can still proceed with the server installation.
After a check that all the pre-requisites are installed the setup wizard will move on to the next step automatically (if the check was successful). If this is the first server you’re installing Microsoft recommends you install the Mailbox server role first (this can be either a Mailbox-only server or a combined Mailbox/Client Access server).
If there is no existing Exchange organization in Active Directory, and you haven’t already prepared Active Directory for Exchange, you will be prompted to enter an Exchange organization name.
The first dialog gives you the opportunity to check for updates to the setup files before you proceed.
Alternatively, you can install the tools on a member server to run Exchange 2013 Active Directory preparation.
For Windows Server 2008 R2 (SP1 or later), in Power Shell run: For other Active Directory preparation scenarios, such as multiple forests or multiple domains, refer to this article on Tech Net.
Running right now at my latest demo, which lets you send anything via email and posts it to a public URL on the web.
After installing the pre-requisites a restart of the server may be required.If you proceed without restarting then setup may be unable to proceed when it detects the pending restart.