There is only one file type that uses the .LMX extension:
Landmark Exchange File
Data file that contains descriptive information about landmarks; contains the name, description, coordinates, address, and category of each landmark; saved in a standard XML format.
LMX files can be imported by the mapping application included with Nokia phones. They are supported by Nokia Symbian-based devices, such as S60 mobile phones.
Updated: November 23, 2009