I'm having a problem when sending some e-mails. Every now and then after sendind new mail I get a message back that says "No Carrier transport for..." and it gives me a list of addresses that it did not send to. I'm using Outlook 2000 and I am on a T1 connection. I check to make sure that the line was up(which it was). Does anyone know why this is happening ie. my mail server is down, invalid e-mail address. The problem only happens on one machine at my office and it just so happens to be the company president. So I can't be absolutly sure a the e-mail addresses were put in correctly.