If you have recordings that you listened to on your computer, using MXIE, and they are no longer there, they should still be on your computers hard drive.
If the recording was in a Group (Operator, Hunt, etc) folder:
Each group the user is a member of will be represented by a long, random integer for a folder name. Look in these folders for .wav files.
Here are the directories you can look into depending on your Operating System:
C:\Documents and Settings\[WindowsLogonName]\Application Data\Zultys\MX Settings\[MXUserName].vm\