The working perfectly does not always work out that easily as illustrated in this thread: Cant set up new Google account - #3 by celloshred
In instances like that, Google most likely wouldn’t provide direct support for eM Client to get things working with their email server systems. Imageway would provide support in that situation due to working closely with eM Client and completing extensive testing to ensure compatibility with eM Client, including the auto-discovery functionality as illustrated here: eM Client with Imageway - #28 by Holbourn
Just another factor to think about if you want a email provider that has worked with eM Client directly to make sure it works in the best and most reliable way possible with their email server systems.