Walkthrough guides for various steps
Change Gmail to trash messages instead of archiving on iPhone & iPad
Gmail defaults to archiving your email in the built in Mail app on your iPhone or iPad. Follow these steps on your iPhone or iPad to change it so it deletes email instead of archiving.
Step 1) Click the Settings icon on your home screen
Step 2) On the latest iOS, scroll to the bottom and click Apps. On older iOS versions look for “Mail.”
Step 3) Scroll down the list of Apps and select “Mail.”
Step 4) Select “Mail Accounts”
Step 5) Select your Gmail or Google email address
Step 6) Select “Account Settings”
Step 7) Select “Advanced”
Step 8) Under the section Move Discarded Messages Into, select “Deleted Mailbox.”
Step 9) Click “Done” in the upper right, and you’re all set!
Following these steps will change the Mail program so when you go to throw something away it will put it into the trash instead of archiving it.