I have not been receiving forwarded website mails to my hotmail ( now outlook account ) for around 6 / 7 weeks

I own a holiday property which has a submission form for enquiries. This was always linked to my Hotmail account. In the past 6 to 7 weeks, this process has stopped. My friend who built the site and hosts it through 1&1 in the UK, also tried to use his Hotmail / outlook account to no avail. He then used his gmail account and enquiries came through.

can I ask

1) has there been a change in Hotmail / outlook preferences since the Hotmail / outlook switchover.

2) Why can I get enquiries arriving at a gmail account but not Hotmail / outlook.

I have no error messages. Clients who have called after no response from me say they are loading info on the enquiry form with no error response and I have submitted myself with no error code at the website end. I get nothing in my junk folder either.

Is there a simple solution or do I require to switch to another e-mail provider? There has been no alteration to my website over this period.

regards

Graham