Email apps, official vs third party

I started to use Spark on iOS (and really liked it), but shortly after I stumbled upon a thread about the security concerns with Spark (and third party email apps in general). The fact that you are handing over your pw/token, and your full email messages to third party servers and the risks associated. I stopped using Spark and deleted my account, but I had a lingering question.

What if you’re using the “official” app of the email provider … specifically Gmail (for @gmail) and Outlook (for @outlook).

Are security concerns mitigated when using official apps since all your information are already on their servers anyway? I understand that apps like Spark, Airmail, etc will lead your email to ending up on third party servers outside of your email provider, but with the official apps are there still third party servers involved in the process along the line because of push notifications or anything else I’m unaware of?

I guess it’s possible with Outlook because they bought Acompli so maybe there are third party servers still somewhere in the chain?

Privacy Galaxy!