Last night, having used my email all day, I got a message saying that Thunderbird could not login to my email account. After booting up this morning it still won't work, so I tried webmail - email address and password not recognised. I tried logging in to virgin media, but it won't recognise me either.
Thank you! Actually I got my husband to change my password, as I was unable to (could not login to virgin media either!) and he is the account holder. Also Thunderbird seemed to have lost my main email and was trying to login as an alias which of course does not work. Having put back the main email and with a new password - all started to work again.