Running your simple test example..
File "/usr/local/lib/python2.7/dist-packages/yagmail/init.py", line 31, in init
self.login(password)
File "/usr/local/lib/python2.7/dist-packages/yagmail/init.py", line 65, in login
self.smtp = smtplib.SMTP(self.host, self.port)
AttributeError: Connect instance has no attribute 'host'
shutting...
Exception AttributeError: "Connect instance has no attribute 'smtp'" in <bound method Connect.del of <yagmail.Connect instance at 0x7fad75949998>> ignored