A bit more information about the different EPiServerMail 4.4 / 4.4 SP1 installation options

1) Install EPiServer Community Integration

Target platform - CMS (5.1.422.256 or later) + Mail Module + Community Module (3.2 or later)

This installs components which allow EPiServerMail to interact with EPiServer's Community Module.  It provides support for:

1. sending mail to users in EPiServer Community with a specific set of attributes;  and
2. sending mail to users in EPiServer Community selected by a User Search.

It installs no databases and makes no database changes.

2) Install Mail on Existing Site

Target platform EPiServer - CMS (5.1.422.256 or later) with or without Community Module. Important: EPiMail 4.3 or earlier must be uninstalled before choosing this installation (see Uninstalling EPiServerMail 4.3).

This installs all components required for EPiServerMail to work. As certain components are shared between EPiServerMail and the Community Module, a new separate database with required tables and stored procedures will automatically be installed for EPiServerMail if the Community Module is not already installed.

3) Install EPiServer Mail without database (When you are mirroring)

Target platform EPiServer - Load balanced environments, with a single database with tables and stored procedures which support the needs of EPiServerMail.

This installs all components required for an EPiServerMail instance to work. By itself it installs no databases and makes no database changes.

4) Install SQL Server Database

Target platform EPiServer - Multiple instances of EPiServerMail in a load balanced environment, without a suitably configured database.

This installs the database, along with database tables and stored procedures which support the needs of one or more EPiServerMail instances.