As a couple we often get many mails & we always try & answer the first 10 or so straight off, the next ten may have to wait a day or so.....but we do reply.
Of course, in my own office it is easy to surf & reply, though some people in open offices will only snatch a glimpse & maybe exposed by unsympathetic bosses.
If I owned a company then I might be somewhat heavy handed on my staff surfing what could be classed as a porn site. In most organisations that could be dismissal.......