You have to consider all platforms, this question does not.
The "correct" answer is not valid.
The official "Security note" from BOL is below:
SQL Mail is not installed by default in SQL Server 2005. For more information, see Surface Area Configuration. SQL Mail is not supported on 64-bit versions of SQL Server. SQL Mail stored procedures cannot be installed on 64-bit versions.
This feature is not just disabled, it isn't present. For those of us that know the difference, it's huge.