There are a few ways to do this.
It does depend on your current setup though, so knowing that would help.
Putting email redirection in place works well.
So all accounts forward email to your main address then everything would be in the one place. You can do this from within MyFreeola.
You will still be able to write from separate addresses depending on how you've setup your email client.
Let us know if that helps and/or what your current setup is.