Which Database is Suitable for My Business?

Database	Features	Suggestion
Microsoft Access	Setup not required	Trial or small business.
SQL Server 2000 Desktop Engine	Free edition with 2G physical file limitation	Small-medium business.
SQL Server 2005 Express	Free edition with 4G physical file limitation	Small-medium business, recommended.
SQL Server 2000 Standard/Enterprise	Not free but without limitation	Medium-large business.
SQL Server 2005 Standard/Enterprise	Not free but without limitation	Medium-large business.

Microsoft Access database
Access database is supported by Windows directly and then not required installation. If your business is not large or you just try AA Mail Server firstly, you can choose Microsoft Access database for convenience. Access database is not stable enough for long time heavy access pressure, and so SQL Server is recommended on most cases.

SQL Server 2005 Express - Recommended!
SQL Server 2005 Express is a free edition with limitation of physical database file cannot exceed 4G. AA Mail Server stores only account information and decoded mail information in database, so that database volume requirement has been reduced mostly. SQL Server 2005 Express is suitable and recommended for small-medium business. See also: Where to download and how to install SQL Server 2005 Express.

SQL Server 2000 Desktop Engine
SQL Server 2000 MSDE is a free edition with limitation of physical database file cannot exceed 2G. AA Mail Server stores only account information and decoded mail information in database, so that database volume requirement has been reduced mostly. SQL Server 2000 MSDE is suitable for small-medium business. AA Mail Server setup wizard can auto download and install it for you.

SQL Server 2000/2005 Standard/Enterprise
Microsoft SQL Server 2000/2005 Standard/Enterprise editions are not free but without any restriction. AA Mail Server stores original messages and decoded attachments in files, so that database volume requirement has been reduced as much as possible. SQL Server 2000/2005 Standard/Enterprise are suitable for small-medium-large all business. ACC+PWD authentication mode is required.