Dear Mr.xxx,
Good morning.
I am writing to share with you the plan of my boss,Mr.XXX to pay you a visit.
In order to thank you for your cooperation these years and seek more opportunities to strengthen our business relationship for our mutual benefits,my boss is planning to visit you recently.
Could you please tell us when you are available?
Hope this coming meeting will bring more benefits to us two!
Your positive responses are warmly awaited with keen interest!
Sincerely yours,
XXX