Why can't I set my downloaded .dm ringtones as text and email notifications?

Question

I have an HTC Incredible 2;  I paid for and downloaded several ringtones from the Verizon store, two of which I wanted to specifically use as the text and email notification sounds.  I then had the already discussed problem of not being able to find the newly downloaded ringtones immediately, but from the postings on here and the Adriod forums, I followed the directions to set up the folders titled Ringtones, Notifications, and Alarms on my sdcard, and moved the downloaded ringtones into their respective folders.  When I opened up the Personalize menu, under Sounds I was immediately able to find the ringtones I'd placed in the ringtone folder, but my phone wouldn't recognize the ringtons I'd placed in the Notifications folder.
I downloaded the app Zedge, downloaded specific Notification sounds (.mp3, and they work).  I also downloaded .mp3 ringtones and then moved them into the Notifications folders, and THAT worked.  The problem seems to be that these are .dm files?  Is my phone unable to read .dm files as Notification sounds?  Or is there something I missed?  Something else I can do?
I looked all over for software that will convert .dm files to .mp3, found a suggestion calling for the deletion of a couple of the lines of code from within the .dm file using Notebook ++, but that didn't work.  I don't remember seeing anywhere in the store that these ringtone files come in the protected .dm filetype; that many players will not be able to play them, and that I won't be able to use them for notification sounds?
Ay one have any suggestions?  Verizon: am I doing something wrong?
Thanks in advance for any help.

Answer 1

Usually when you purchase ringtones from the Verizon store, you can only use them as ringtones. Since you have a smartphone, an app would be the best bet. You can find almost any song you're looking for in a free ringtone app, there's no need to purchase them.