No CREATE_TIMEDATE column, can I still export records inserted within last 24 hours?
In SQL Server 2005 there is no hidden column for the date something was added to the table.

the best solution would be to add a new DATETIME column to the tables you are looking to export the last 24 hours if this is to be an ongoing process (you could put an insert trigger on the table to make sure the column is populated).  Entries from before you started tracking the creation date can remain NULL or be set to something like '1900-01-01' (the "0" date in SQL Server).

If changes to the table are not permitted then the only option is to query the table at midnight and then again at midnight the next day (a SQL Agent job would be the best way to accomplish that).  However this only works if the primary key is always increasing in some manner (Identity column for example).  Otherwise you wont know what range you need to select, (IE if your primary key is email for some reason you wont know when a record was inserted based on the sequence).

I would also suggest a table to hold those results from the query every 24 hours so if you need to rerun the export for a specific day you would have the information you needed to do that.