How to delete emails on iPhone (not archive)

I use the iPhone app for my University Gmail account. I have discovered that when I delete emails from my phone, they actually get archived in "All Mail". I think when I delete them on my laptop they actually get deleted. Is there a way to delete emails on the iphone so that they are GONE, not taking up storage space? Otherwise I guess my best option is to wait until the evening and delete emails from the day on my laptop. This is so annoying... I have 138,000 emails in my All Mail (I've had the account for 30 years).