Father sent unwanted mail to my workplace I have been out of touch with my father for a few years.
I have tried detach from him but maybe he hasn't noticed.
I have not explicitly told him that I would rather not deal with him.

He previously had no means of contacting me directly, but now I can be 
found in the online via my workplace. So he has sent me a letter there.
I have not opened it. I feel pressured to contact and appease him.
But I do not want to appease him and most importantly I need him to stay
the hell away from my workplace. He might use this as a pressure point if 
he feels scorned.

Help?