Multi Location SMTP Server Or Email Platform

for a SMTP server / hints at how it might be done to accomodate the following :

One single email will be sent. If it doesn't get sent on the first try by one server, another server at another location will attempt the connection and will send out the email then.

Is there a prebuilt solution that anyone knows that will help with these things ? If not, do you know of any ways that this might be possible to be done - even if you don't know the exact details of how it should be done - any help in finding out something like this would help .

Note :
Linux / Windows / FreeBSD / Solaris is fine. So whatever OS it is, it's fine by me.