The virgin.net domain has a hissy fit on at the moment. It isn't working properly. Explains exactly why you are seeing what you are seeing, or rather not seeing. Nothing you can do. You might be able to access your mail direct via VM web mail for the moment.
Superuser 2017/18 Use Kudos to say thanks Mark answer as "helpful" only when the problem is solved Please don't send me private messages unless I ask you to. I do not work for VM. The advice I give is based on my best understanding of VM policy and practice. You rely on it at your own risk.