What Matt said... basically something like:
<cfif structKeyExists(FORM, "send") and FORM.send eq "Send">
<cfswitch expression="#Form.team#">
<cfcase value="teama">
<cfset emailTo = "joe.bloggs@example.com">
</cfcase>
<cfcase value="teamb">
<cfset emailTo = "teamB.email@example.com">
</cfcase>
... etc
<cfdefaultcase> <!--- default if all else fails --->
<cfset emailTo = "contact@simpleform.com">
</cfdefaultcase>
</cfswitch>
<cfmail from="ContactForm" to="#emailTo#" subject="SimpleForm" type="html">
...
</cfmail>
</cfif>
Also note the use of structKeyExists instead of isDefined - generally considered better practice.