OK, I'm not sure how I can implement what you're asking for. Photo Mechanic won't be part of the file transmission and unless there's some metadata in the file with the transmission time, then PM won't have the data it needs to accomplish the task.
If you were to use Live Ingest and apply a Metadata Template, you could put the {now} variable in one of the fields and then create a custom sort on that field.
-Kirk