Update.....
When my inlaws called Sky to terminate they offered a free 2nd room install of a free Sky+HD box with £30/month off the bill so they are staying with Sky

.
As they are low demand broadband users the Sky broadband offering they get is enough. With two laptops and three xbox360's I need more bandwidth than Sky can provide to my address !!
Some of these retention deals seem mad to me. Anyway thanks for the advice on the email situation..