I'm trying to set up email notifications using smtp-relay.gmail.com, mainly so I don't have to take up a paid seat in gsuite and I'm running in to some issues that I'm not sure how to solve but searching around and anything I can find shows people are using smtp.gmail.com instead. 

Is anyone using googles SMTP relay or have you tired and ran in to issues that means you cannot use it? I would be interested to see if I'm going the wrong route and should try something else.