Do I need to mail anything after e-filing?
Not unless we tell you to. The goal of e-filing is to eliminate as much paperwork as possible.
There are a handful of filing situations where you might need to mail something after e-filing, but we'll let you know. Otherwise, don't worry about it.
Having said that, we strongly recommend that you print a copy of your return for your records after your e-filed return is accepted. More info