Challenges with Email Servers (Examples)
One of the reasons why I wrote the test script the way I did is to help people isolate challenges with SERVERS vs PROTOCOLS or TRANSPORT.
Sample case one: Google and Insecure Apps
Valid credentials were provided.
More About this here: https://support.google.com/accounts/answer/6010255?hl=en
Sample Case 2: Yahoo No Longer Responding to Service But Port is Open
