Since you don't use any of the method's arguments
sender and
EventArgs, you can simply call
sending(null, null);
from anywhere in your code.
On the other hand, since neither of the arguments is used, you could omit them altogether.
Windows Forms is an event-driven architecture. Deciding what event to call your method from is left to you.
Should there be no event but you want the data just to be coming on its own, you have to use a timer to generate such an event. There are
three Timers available that I know of. For their differences, have a look at the linked MSDN pages.