Classic ASP Email Validator Function

I need a compact, reliable emailcheck() function written in Classic ASP (VBScript). The call will look like

x = emailcheck("EMAIL")

so that the surrounding code can decide whether to send or block the address.

Scope
• Accept only a standard email format: (lower-/uppercase letters, digits, dots, hyphens and underscores where allowed).
• Reject any address that contains spaces, the HTML non-breaking space entity “ ”, its numeric form “ ”, or similar ASCII control characters.
• Fail the check if stray characters appear before or after the address—no trimming inside the function; the validator itself must detect and refuse them.

Deliverables
• A single .asp (or include) file containing the emailcheck() function, well-commented, regex-based or equivalent, returning Boolean True / False.
• A tiny demo page that shows the function in action with both valid and invalid samples.

Acceptance
If the demo page correctly flags all provided test cases and I can drop the function into my existing Classic ASP project without extra dependencies, the job is complete.