FYA - For Your Action
FYA is a most common abbreviation used while writing a corporate email. It is used in a situation where a recipient is informed that 'there is some work in which your action is required' or to inform the recipient that he is being given a task.
In other words we can say, that the sender doesn't know what to do, so he is passing the work to recipient.
FYA can also mean For Your Attention, For Your Approval, For Your Acknowledgement or For Your Awareness. The correct full form depends upon the situation in which it is used.