As far as I know, setuptools doesn’t support using a list of strings in order to specify multiple authors. Your best bet is to list the authors in a single string:
author="Foo Bar, Spam Eggs",
author_email="foobar@baz.com, spameggs@joe.org",
I’m not sure if PyPI validates the author_email field, so you may run into trouble with that one. In any case, I would recommend you limit these to a single author and mention all contributors in the documentation or description.
Some sources:
This has been registered as a bug, actually, but it seems like support for multiple authors was not implemented. Here is an alternative solution. Here is an idea for how to provide a contact email for a project with multiple authors.