To elaborate on that last post, the ability to recall or "unsend", while a feature in some environments, is a proprietary technology. Generic mail applications that conform to the SMTP/POP standards, don't have such a feature.
I know in an Outlook/Exchange environment, that is a function specific to Exchange and only works when sending mail compatible servers/clients. I would imagine that AOL mail works in a similar fashion.
No, it won't work with Apple mail or any "real" POP client.
An extremely simplified explanation is this:
It can happen with AOL when you send to an AOL addy because in a very generic sense, the email never leaves the AOL server. This is why you don't need to put the "aol.com" at the end of your AOL address when you send to an AOL addy from an AOL addy using AOL software. You aren't really directing the email anywhere outside the AOL domain, you are just posting it to a box on the AOL server.
When you unsend it you simply take it down from the server. It is a similar principle with Exchange servers.
With "real" POP emails, the email must then travel from one server to another and you thereby lose the ability to "un"send it.