shadower

I use outlook as my email client. Mostly I can send attachments, such as pps, jpeg etc, without problems to all my addressees. A couple however don't receive the attachments. I know that this is probably a setting on their pc's but it has only recently happened. I remember making a change to my email settings recently in how it sends messages but can't quite recall what I did. Can anybody point me in the direction of the setting that I should change. Thanks Eric.