Your friend is coming next month but you have urgent work and hence you cannot receive him/her at airport. Write a letter to friend, in your letter
-Apologize to him
-Explain situation
-Suggestion for arrangements
Answer
Dear Stephen
I am happy to know about your next month visit and to read your wish of being received by me. Stephen, it would have been my pleasure to welcome a great personality. But I am afraid, unfortunately the opportunity has slipped out of my hand and I feel very sad about it. But I have made alternative arrangements to welcome you.
Last day, my team leader called meeting and announced a site visit to Dubai in first week of next month. This announcement cancelled my plan of taking leaves and skipping the site visit is like, breaking a rule for senior software developer like me. Because of this, I will not be able to receive you at the airport and I hope you will understand my situation and forgive me this time.
Although I will not be there, my absence will be substituted by our old friend John. He is very happy to know about your trip and is ready to welcome you at the airport. Please share your arrival time so that I can inform John before hand.
Hope to meet you after my Dubai visit and wishing you a safe and happy journey.
Yours truly
Amanpreet Kaur