Email

Restart the phone and test again.

Then, Settings, Mail, Accounts

Are all the email accounts there and toggled on?

If they are then try removing an account and adding it back

(Not iCloud, with that just Settings, your name, iCloud and toggle Mail off then on)

how do i remove an email account and adding it back on my iphone? My laptap receives emails just fine...but not my iphone

Assuming you are using iPhone Mail app:-

Settings, Mail, Accounts

Tap on an account. delete account.

Settings, Mail, Accounts, Add account

Ths above does NOT apply to your iCloud account