I'm not certain, but I don't think CDONTS will be available. Don't think it'd be part of the install of SQL Server Express, but it *might* be part of the OS install, or might come with Microsoft Office if you've got the right parts installed. You're more likely to have CDOSYS I think, if it's newer version of Windows. In googling a bit it looks like maybe SQL Server Express does have email stuff on the SQL Server side, but the core email components (DLLs) are not included and emailing-related services are disabled and buried.

Sorry for the waffly answer. 🙂