Jason,
Active Army Medical Retirement and I received no email.
In my case I was at the VA liason at Benning getting my claim in (this is almost immediately after I received my DA 199) and the woman advised me to take the 199 down to retirement services so they could knock out some outprocessing tasks, namely the Survivor Benefits Plan paperwork.
I went down there and they told me the authorization shows up in their system and they usually contact the highest echelon S-1 (in my case, brigade S-1) when the authorization comes through, this is of course, if retirement services have no other way of contacting the soldier in question. If the soldier is proactive (which is the usual case) they simply call him or her directly and tell them to come on down.
At Benning, retirement services physically cut orders with you sitting right there. They had access to iPERMS and finance so they could quickly throw together some orders. The main reason the soldier has to be present, aside from actually receiving orders, is so the retirement personnel can determine whether or not to factor in the 20 days permissive TDY and to fill out the Survivor Benefits Plan paperwork (though, the SBP paperwork can also handled during retirement briefings prior to receving orders).
There was (99.9% still is) a disconnect between PEBLO and retirement services at Benning and I would have never known to goto retirement services if it wasn't for the nice woman from the VA. I presume if one is not directly in contact with retirement services, the most likely way to find out would be through a phone call from a soldier working in the company level orderly room.
Aside from the waiting, getting authorization and orders was relatively painless when compared with trying to clear CIF!