I was wondering if there is possibly any way to make a program that checks my
juno mail box and deletes any mail that i recieve from a sender who has sent 4
or more and keep any e-mail from a sender who has sent three or less.  My
account has been mail-bombed several times and it is quite annoying.

Of course, it is easy.  Just write a program that reads your juno
mailbox and does what you want.  Of course, you have to know the
format of your juno mailbox, and possibly and index files that are
used to get into it, but there is nothing mysterious about writing
such a program, except knowing the file name(s) and format(s).
                                joe