I am using Windows XP home and Outlook Express 6.0
I have in the past added music to my emails. I produced one today this time adding a song. I sent it to myself and it worked. I sent to to my self at Hotmail and it worked. I sent it to my brother and it didn't work!!
Do you think it might be an anti-virus program or IE6 security thing? Presumably the music file attached to the email is seen as an "executable", and we know that in the past these have been exploited as virus carriers. As to why it plays when sent to your home system address and your Hotmail account, maybe these have been set by you (or are treated by XP as) "trusted sites" as they are of your own creation, in a way?