How to delete emails on iPhone?

I was going through my emails and realized I had a bunch of old YouTube notification type emails. I used this method to try to bulk delete them:

https://www.iphonelife.com/content/how-to-quickly-find-mark-delete-all-emails-one-sender-iphone

It seems to work but even after deleting them out of my trash folder they're still in my inbox. I've tried countless times and they won't delete, does anyone know what to do? Or a better way to try to delete them?

How to fix my iPhone?

I have an old iPhone 6s that hasn't been activated since the 7 came out? But I still use it sometimes and it's got a lot of information on it. I cut it on and it was asking for Wi-Fi info like it had updated or something but I set that up then it said it was activating and may take a minute then said activation error and won't do anything. How do I fix it. At least to back it up and get my stuff

How can i unlock a locked iphone?

I just need the device pin not the icloud password. I don't have the itunes account anymore. I seen a website called imyfone software that can unlock the phone but i don't know if it will delete everything off the phone or just the password.

Should i get the iPhone XS max?

I currently have the iPhone 7, but I'm not sure if I should upgrade. I know the max is quite pricey, but I'm debating whether or not it's worth the upgrade. Should I head and upgrade or wait till next year?

Most online dating sites are a scam because they are usually run by fraudsters who work in call centres. True or false?

Fraudsters who work in the call centres would use photographs of women to entice unsuspecting people and tell them what they want to hear, which is a money spinner.

But people who are gullible enough to subscribe are usually disappointed because the fraudsters are usually men instead of women, but they have no romantic design whatsoever.

These iPhone dating apps are mostly a scam, which is a complete waste of time and money.

True or false?

Is there an iPhone 9?

They made the iPhone 8. Then there was the iPhone X which everyone called the iPhone 10 if I remember. Now the XR, XS, and XS Plus are referred to as the iPhone 11. Did they skip 9?