I've discovered just recently that I have not received all of the email that has been sent to me.

I have my own domain name and I use this to forward email directly into my outlook.com account and more recently into my gmail account as well.

For some reason I have in the past received an email from someone (who is also in my outlook.com contact list) but for the past month or so I haven’t been receiving their emails in outlook.com

I added a forwarder to my email account (at my domain level to gmail) and this is successfully receiving the missing emails that outlook.com isn’t.

I have checked my blocked list and my junk folder but they are not there either.

Can anyone shed some light on this problem as I'm worried there is potentially a lot more than I am missed?