Installing a python package that is not available in anaconda (smtplib)

First, the real environment manager is conda, and anaconda is actually a collection of generally used packages for scientific calculation, so it is not necessary for creating an environment.

Second, smtplib is a built-in package for both python2.7 and python3.x, so there is no need for installation. You can import it without installing any other package.

Finally, what source activate <venv name> really does is that modify your environment variables in the current console. That also means change the path of command python and pip and the path where the python program looks for installed modules. In a word, source activate <venv name> activate a separated environment for python.