https://github.com/kylejb/py4e-student-repo/blob/master/2_Python-Data-Structures/ch_09/ex_09_04.py [updated url -kylejb]

Think about what you wrote and lets walk through it

words = line.split()

First off, what is line? It's undefined at this block, but let's write the code I think you had that's breaking.

for line in handle:
  words = line.split()
  for word in words:
# Parameter to focus only on lines starting with "From "
    if line.startswith("From "):
      email = words[1]
      print(email)
    counts[email] = counts.get(email, 0) + 1

Ok, let's stub some data

line = "From [email protected] on Dec 13 2019"
words = ["From", "[email protected]", "on", "Dec", "13", "2019"]
Now you run for word in words, which is 6 iterations of your loop. That means 6 times you run this code

    if line.startswith("From "):
      email = words[1]
      print(email)
    counts[email] = counts.get(email, 0) + 1

For the exact same line. Before you even get to line 2 in the file, you've added my email 6 times because you're checking for every word. You just want to check each line in the file.