I have developed add in for outlook 2013.
Now i want to deploy it to client computer.
I have created setup file and in result, i got one executable file.
Now my question is, if my client have 100 employee and he wants it for all his employee,
then do he has to install it in all of his employee's computer or is there any other alternative.?
Yes, it has to be installed on all computers. An Outlook add-in is no different than any other kind of software that requires installation. Your client can use any of the numerous software deployment tools that are available to automate the distribution and installation of your solution.