So, here is what has just worked for me;
I had been using the same email password for some time, across my different devices, for my virginmedia.com email address
I have just reset my email app password
I went to my virgin media and logged on. I had reset that login password yesterday to 'start afresh'. I was able to access my virgin emails there (webmail).
I then followed the change email password links
https://www.virginmedia.com/help/virgin-media-mail-unavailable
This generated a new password for the apps like xxxx-xxxx-xxxx-xxxx
I then copied this into one of my email apps (on a Windows 11 laptop) and it has worked - I can now access emails there. I now need to go and enter this into my other email clients (apps). Hopefully they will all work.
It would appear that, in my case at least, VM have introduced this new security measure and it has stopped my emails working (from yesterday). I don't recall receiving any notification about it, but maybe there was?
Try doing the same to see if it helps in your case.
Here's the text from the link above;
Step 2. Next, we need you to generate a new password to be used specifically for signing in to third-party mailbox apps (like Outlook or Gmail) to access your Virgin Media Mail emails. Even if you don’t use these apps to access your emails now, we still need you to reset the password anyway to fully secure your account.
- Sign In to My Virgin Media
- Go to Account settings, then Account details
- Tap Manage next to Manage your Virgin Media Mail app password under Virgin Media Mail
- Then, under Virgin Media Mail app password tap Get password
- Continue the flow and a new secure password will be generated for you
- Update any third-party apps that you use to access your Virgin Media Mail emails with this new app password
Please note that as this password is separate from your sign in details for My Virgin Media (or any Virgin Media apps) this won’t affect your My Virgin Media password. So, if you check your Virgin Media Mail emails through My Virgin Media or at mail.virginmedia.com, you'll still only need your My Virgin Media password.