The contact list can be exported in CSV file, then you have to do some modifications to the file so the Gmail can import it properly.
To export the contact list from old AU system, please follow the steps.
Step 1: Login to portal.au.edu or click link "Old Portal" in home.au.edu
Step 2: Select “Address Book” from the menu in left panel.
Step 3: Select the book that you would like to export, normally, it should be your name.
Step 4 : You should see the contact list at the main panel, select the contact that you would like to export or click at the top most check box to select all contacts.
Step 5: Select “Comma separated values” for “Select the export format:”.
Step 6: For the radio box option, choose one:
6.1 If you would like to export only some contacts as you selected, choose “Export only the selected contacts".
6.2 If you would like to export all contacts choose “Export the following address book completely”.
Step 7: If you choose to export all contacts, you have to select the address book again, and it should be your name.
Step 8: Click “Export” to save the file. You can name the file as you wish but you have to leave its extension as ".csv".
Step 9: Using MS Excel to open the file.
Step 10: Deleting all columns except "firstname", "lastname" and "email".
Step 11: Renaming the columns so they become "First Name", "Last Name", and "E-Mail Address".
Step 12: Save the file as ".csv", do not change the extension to ".xls".