Mark All Gmail App. Go to the email that we want to mark as read. Unfortunately it's not currently possible to select all messages at once using the gmail app for ios.
Type is:unread in the search box on top and click on the search button. If you only want to delete certain emails, you can select them and click delete forever. — google mail (gmail, google apps for business and education) — microsoft (hotmail, msn mail, ms outlook, office 365 and live) — yahoo mail (previously, ymail) — aol (alto) — gmx.
In the extended menu, scroll down and click on.
Log in to your account by entering valid credentials. In the top right, tap unread. Gmail is built on the idea that email can be more intuitive, efficient, and useful. On your android phone or tablet, open the gmail app.