You have the following errors, all of which Python tells you:
At line 43:
userChoice = ""
But all the following lines spell it
user_choice
.
At line 47:
print(int(input("Enter index of email you want to read: "))
I think you mean something like:
index = int(input("Enter index of email you want to read: "))
At Line 54:
print(add_email(Email, email_contents, from_address))
But Email at this point has no meaning at this point. I suggest you take a look at
9. Classes — Python 3.10.5 documentation[
^].
There are probably other errors which will show up in your testing.