Finding the Exchange Mail Pickup and Replay Directory Folder Location in Your Exchange Infrastructure

Use the following powershell command to return the mail pickup folder location from all your Edge and Hub Transport servers.

Get-TransportServer | Fl name, PickupDirectoryPath
If you are interested in a single server add -Identity:
Get-TransportServer -Identity “Server Name” | Fl name, PickupDirectoryPath
Where “Server Name” is the Exchange box you are interested in.