The text quoted below is from another post in this forum. Following this procedure should get your gmails to show. The most relevant part is the last paragraph. Hope this helps.
......................................................................Quote from another posting................................................................................
If you use the standard Samsung email app, then you will be able to access all current emails received SINCE you connected your gear, and in my case, that DON'T come in while the Gear S2 is charging on the cradle. For some reason I don't get email from overnight when the device is charging. So, using the standard Samsung email app you will be able to use the Gear to navigate your current emails from your watch, read, delete, and reply. It works pretty well.
But...
If you use the Gmail App, or any third party app, then you will run into issues. The first issue is that the notifications for third party*apps*disappear from the Gear S2 when you clear those notifications from your phones notification shade. Try it for yourself. It's crazy. But while the notification is available on your Gear S2, you can interact with it just like you would expect. You can reply, delete, mark as read; it's a pretty crazy thing to think about, really.
I hope Samsung opens this up to more customization. Right now I feel stuck with using the Samsung*apps, specifically the messages app and the email app. I would prefer to use the Google*apps.
My work around is to use the Gmail and Samsung's email app on my phone, but only turn on notifications on the Gear S2 for Samsung's Email app. This way I can interact with my emails on the phone through Gmail AND still get persistent emails on my Gear S2. The issue then becomes that since the Gear S2 does not sync my emails coming in while the device is charging, when I wake up in the morning I've got stuff on my phone that will NEVER show up on my watch... it's a bummer, but I deal with it.
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