Get off Gmail, use Thunderbird (and soon Thundermail).

https://www.androidpolice.com/giving-up-on-gmail-on-android/

I'm finally giving up on Gmail on Android, here's why

Life after Gmail

Android Police

@ryanleesipes

Another *valuable* characteristic of the #Thunderbird client is that it can display an email's full headers.

All too commonly, an ESP's native client will NOT display the headers. (I'm looking at you, Gmail and Outlook.)

Worse, those same clients will often display only the "spoofed" sender details.

It's almost like their devs sat down and thought,
"How can we simultaneously make our app worse AND increase the likelihood of our users getting scammed? ... I've got it! Let's remove any possibility of seeing the email headers within our client app!"

I thank God, and Mozilla, for Thunderbird.

@TimePencil thanks. Yes! It's important that people are able to access all the information in the headers if they want! (why make that difficult/impossible to access to begin with?)

@ryanleesipes

Absolutely!
Thunderbird's ability to show the headers has saved my parents, twice, from being victims of scammers.

Thanks again, Team Thunderbird!