iPhone keeps getting Hotmail reminders

[Skyedriver]

My sons' iPhone 7 (which was bought s/h over 6 months ago, cleaned and factory reset before it arrived) has started getting pop ups from Hotmail telling him to log into his email account. He hasn't a Hotmail account, has a Gmail account and an Outlook account.
Is this some new sort of a scam or just Hotmail trying to get him to sign up? Don't think it's the original owner as it's just started happening.
thanks in advance

[Dracoro]

Pop up when using Safari?
Just go into Settings>Safari and set Block pop-ups.

[bernie_eccle]

I neither have an iPhone nor an apple account but am receiving the same -scamtastic!

[macstorm73]

I was getting the same, found out that I'd been getting spam calendar invites that were being auto accepted. Resulted in loads of weird reminders

[Sheepshanks]

Hotmail is Outlook.com now, isn’t it? Apart from in the email address itself, I don’t think the Hotmail name is used anymore.

[nikaiyo2]

Outlook and hotmail are the same.

Does he get emails on his phone from Outlook? If the password on the phone no longer matches the outlook account it will ask you log back in.

[Skyedriver]

Thanks everyone, pleased (not really the right word) that it's not just him.
He uses Safari but pop ups were already blocked.
He uses an Outlook account on the phone but never had a Hotmail account.
Strangely enough this has all stopped now, as quickly as it all started.
Mysterious..

[Skyedriver]

And have started again .............

[Skyedriver]

Dracoro said:

Pop up when using Safari?
Just go into Settings>Safari and set Block pop-ups.

He did that, no change

Strange thing is it happens weekdays not weekends.