I'm unable to send e mail with attachments using my new Verizon DSL (which I am coming to hate, btw). My roommates were having the same problem, and we figured out that the problem was that the MTU (maximum packet size) was set too high (it was at 1500 and needed to be at 1400 or something). They were able to change it in System Preferences -> Network -> Built in Ethernet -> Ethernet tab -> configure manually. I, however, am using airport, and can't find an equivalent option. Does anyone know how to reduce the MTU using airport? thanks.