When I migrated a classic ASP Website I noticed that ASPMail (or SMTPSvg.Mailer) from ServerObjects no longer works under Windows Server 2008, let alone 2008 R2 and 64bit. Others have failed as I did, noticing the same error (Server.CreateObject failed, error 800703e6 - Invalid access to memory location) - with no solution or to resort to other mailing methods, for example CDOSYS.
Not wanting to change any code, I resorted to writing a simple wrapper around the .NET MailMessage class to create an interface-compatible component to the SMTPSvg.Mailer class.
Far away from beeing identical in behavior and only tested for the specific website, you can download the source here.
bin/1.0/SMTPSvg.dll
The component must be installed in the GAC to use it from classic ASP. Contact the MSDN Library on how to do that. http://msdn.microsoft.com/en-us/library/dkkx7f79.aspx
GPL2 or newer, contact me if you feel you need something else.