Photo's need to be stored somewhere where ebay can pick them up, this is usually on the C: Drive. The pictures should be detached from the email and saved on the C: drive somewhere. Usually you can right click on the attachment and select "Save Picture as.."
loosehead is quite right but also they need to be jpegs and be about 85 kbs or less which can be achieved by lowering the resolution to 600 dps which is ideal for posting on the web otherwise ebay has trouble receiving it.if this don't work sometimes ebay recomends you download a little programme from them when you post your pics to help you upload them.it should ask if you want to do this when you submit them.