If you want to make sure an email address is valid you can use a Regular Expression to match the correct pattern. Email addresses used by CFMAIL must be valid for the email to go through. Use this block to check if an email address entered from a form is correct:
<cfif REFindNoCase("^(.+)@(.+)\.(.+)$", Trim(FORM.email))> <cfset theEmail = Trim(FORM.email)> <cfelse> <!--- email is bad, set it to something else ---> </cfif>
Then you can use VARIABLES.theEmail and know that it is a correctly-formed email address. This only makes sure that it might be an email address, it does not guarantee that the email address actually works. That is up to luck and your mail server.