We have three sites connected via smtp connectors, these are exchange servers in the dame domain. Site a, B and C for this example. Today we seem to have a problem sending email from site B to site C, C can send to B without a problem and b can send and receive from A, can can send and receive from both B and C. Its only B sending to only A, messages queue up and just stay there. Sometimes one will get through but the rest just stay. any idea on how to start trouble shooting it?