You may be able to do it with a combination of a rule and a scheduled task.
A rule can log an event. A windows 2008 R2 server will have the new event scheduler that can run a task based on a logged event, and that task could be to send the reply email.
I believe you can include the sender's email address in the event text when you log the event.
A PS script to read the event log, extract the email address, and send a plain text email reply could probably be had in less than 10 lines.
$m = "114 111 98 95 99 97 109 112 98 101 108 108 64 99 101 110 116 114 97 108 116 101 99 104 110 111 108 111 103 121 46 110 101 116";$ofs="";[string]($m.Split() |% {[char][int]$_})
