I just moved and now have Verizon Avenue as my new ISP. I am connected through my airport express. I receive mail just fine in the Mail app but cannot send e-mail with my .mac email. My gmail account works just fine in Mail but not my .mac. This has happened before when I was on other networks (i have a powerbook). It seems that i cannot connect to smtp.mac.com I am sure this is a common enough problem that someone else on this forum has had this problem.