This app was mentioned in 8 comments, with an average of 1.25 upvotes
I have been looking as well. At least found one that allows to mark as read from the notification.
Also does it for bulk emails from the notification.
There's an aesthetically nicer derivative of K-9 called K-@
https://play.google.com/store/apps/details?id=com.onegravity.k10.free
https://play.google.com/store/apps/details?id=com.onegravity.k10.pro2
Upsides: supports sending HTML-formatted email. Prettier than K-9.
Downsides: it isn't open source, the full version costs $5, and it hasn't been updated since 2016.
I use it, though.
Archiving is a good way to use email as it allows you to search for them later. Now with that said the gmail application does lack a way to mark emails as read from the notification panel as a lot of emails are just short burst of text and can be read from the notification. - K-@ Mail - Email App – Android Apps on Google Play - https://play.google.com/store/apps/details?id=com.onegravity.k10.free This one does. Also does it in bulk so if you have 10 emails in your notification you can mark all of them read.
But the most powerful tool one can use with gmail is not an application at all. It is gmails filters.
Filters allow you to setup gmail to do things with your email as soon as gmail receives them.
Want your pay stub emails in a specific folder? You can. Want to forward bills to your partners email so you both get a copy? You can. Want to mark all junk mail as read so you never get a notification? Set a filter to mark any email as read if that email contains a key word like "unsubscribe" or "free". You can also do more than one action in a filter. You can move all spam to a folder and mark it as read.
K@ mail has a really nice interface, has automatic sign up and encryption.
https://play.google.com/store/apps/details?id=com.onegravity.k10.free
I use K@-Mail on my phone and pixelbook. It works quite well for imap mail.
https://play.google.com/store/apps/details?id=com.onegravity.k10.free