Open DM File
DM are usually audio files, although they can be of any type, that have been encoded with DRM (Digital Rights Management) copy protection, especially used by some cell phones for ringtones and other media clips. It can also be used for other digitally signed mobile applications, on Nokia cellphones.
You should know that they are only compatible and can be opened using an authorized cell phone.
It is important to note that audio files in DM format cannot be converted to another playable format such as MP3 due to the fact that they are protected with DRM. Only the device that is authorized to play the file will be able to open it.
However it should be considered that not all DM files are protected by DRM, therefore these can be played as MP3, just by changing the extension. This last action can ONLY be done with audio files.
Some DM file formats can be opened with the Paradox Data Model, which was acquired by Corel in the 1990s.
DM is also used as an acronym for a number of other technical terms such as direct message in the context of the social networks that have this service, also as device manager, digital media, document management, download manager and probably others.