> On Travis, 'Documentation tests' passing is apparently required.  Line 23 of nntplib.rst is ">>> s = NNTP('news.gmane.org')"  I use gmane and occasional failures to respond are routine.  Being able to merge should not depend on this external site.

Python test suite uses many external services:
https://pythondev.readthedocs.io/infra.html#services-used-by-unit-tests

You should all be skipped if the "network" resource is not used, which is the default.

Many tests were modified to catch network failures and ignore the test in this case. test_nntplib is known to be very fragile: it doesn't handle network issues.

I would suggest to remove functional tests which depend on external servers, since these tests fail often and nobody seems to care of test_nntplib.