Dear Alistar, Hope all is well with you. First of all, I'd like to apologize to you since I won’t be able to visit you in Australia next week because of some important event.
Dear Oliver, Hope you and your family are doing great. I know that you wouldn’t like to hear what I am just about to say, but it looks like I won’t be able to visit you this coming summer, during mid-July, as was the plan, because I will have to stay in my country for an important event.
Dear Albert, Hope you are doing fine. I have been eagerly waiting to meet you in a few days and spend some pleasant time in England.