Customer has about 10 queues but dozens of 800 numbers and inbound mailboxes with different greetings. Currently they go in manually and change each mailboxes' greeting when they have high call volume.
I'd like to do a token that checks "highvolume.txt" for "1" and if = "1" it plays greeting 2 instead of greeting 1. For some reason I can't quite wrap my head around it.

Or if it's easier to do in the ACD VA ports, I can't figure out if the Enhanced will override the Initial, the Periodical, or all of them, and play the announcement "high call volume".

Yes... it can be done... I had to go find my notes on this...

I had a similar situation where a customer wanted an 'emergency' greeting to play whenever they had an emergency... here's the relevant programming for an IVP8

Set the initial entry to 900, instead of 990.

900 Entry G(901)
901 Emerg? @Z(e.txt)G(990) Done Chain: 992
[Check if e.txt exists, go to Emergency box if yes]

Notice that you're not actually playing a different greeting, you're going to another mailbox...

To toggle the 'e.txt' file:

8256 Toggles Emergency Message on/off
8256: Entry for Emergency Box... Ext: @G(8257), Done/RNA/Busy - 8257
8257: @Z(../901/e.txt)P(G1)X(../901/e.txt)H (Test for e.txt - Create e.txt)
8258: @Y(../901/e.txt)P(G1)H (Delete e.txt)

Now, just program a one touch key to go to mailbox 8256

I hope all this makes sense... it's from my notes about a job I did several years ago...

P.S. I don't recall why I didn't do something like: 'if file exists, play greeting two' - but I know there was a reason I simply switched to a different mailbox.

Maybe I just couldn't figure out how to do it right...

That might work, although I'll have to do a lot of modifications...
Perhaps I can send all the transfer to ACD mailboxes point to a new mailbox that stores the %P (previous mailbox) in %S0, then plays the message if e.txt exists and then transfer to %s0.

At least the part of the code that creates and deletes a 'flag' file will work just as is...

eg: Mailbox 800 has this in the extn field
@P(G1,xxx)
this will play the greeting 1 of mailbox xxx the continue to play greeting of mailbox 800.

I used this on a site that had 100+ mailboxes with a DID pointing to each one for reporting reasons and they played the same greeting.
The main message could be changed in one place and effect all 100+ mailboxes.

You could alway use the enhanced call management with the Calls > xx so only when calls exceed the value xx you will do the action that plays a different VA prompt.

My question about the VA ports is whether the enhanced call management will override the initial announcement or the periodic or both?

Yes it will based on the criteria set for the enhanced call management.

It looks like you would have to know a bit about using scripts, but looks like you could setup some kind of announcement that if calls waiting is greater then X, then make an annoucement. Not sure how often this would repeat.