Isabel2
I have moved your post and created a separate thread for you so that your issue is kept separate from the other Blueyonder errors. The thread you originally posted on was dealing with a completely different email issue to yours.
The Ox800CCOE error code is a Microsoft Outlook code and it just says that Outlook cannot connect to the email server. So, sadly, it is particularly unhelpful in diagnosing exactly what the underlying problem is or how to resolve it.
It could be an Outlook problem or a problem with your VM account. The fact that your account is a Blueyonder account is not significant (in my opinion), because just as many people are reporting problems with Ntlworld and Virginmedia.com accounts 😉)
The first thing i would do would be to see if you can sign into your Blueyonder account directly through the VM webmail service on their website. Enter your Blueyonder email address in this link https://mail2.virginmedia.com/ and then enter your password when prompted.
If you cannot access the account it strongly suggests that the problem is with your Blueyonder email account. Post back with the error message you get and someone here will be able to give you constructive advice on how to resolve the problem. It may need a password reset.
If you can access the email account on the website it at least means you have a temporary workaround to manage the account. However, the main thing is that we know to concentrate on identifying the issue with the SMTP/IMAP/POP2 processes that Outlook uses to access your Blueyonder account, That could be at the Outlook end or again it may need a password reset and the use of VM's new mail app password.
Try accessing the account on the website and report back.That's the first simple step to identifying the cause of the problem.
Coenoby