I recently went through a slew of hurdles due to my email account not receiving either authentication or support emails. I can make note of a couple things:
1. I was using Yahoo, I had flagged an authentication email as “not spam” which did indeed cause me to stop receiving those messages.
2. I submitted the issue and did get a response, I was told I would be bumped to a Senior Representative. After that, however, I stopped getting any emails from support as well.
3. I read this post and switch to gmail to submit again. It all worked out, and the agent apparently disabled authentication on my account so I could finally play again. If not for that, I doubt the problem would be fixed.
I know it isn’t much, but it is something at least, hope something in there helps!