Please explain what you did before the error message? Your image does not show what part of Thunderbird you are in, or what function you are using. Was this opening an old email or downloading new emails? Do old emails show in Thunderbird at all? Do new emails appear when you open Thunderbird? We just need to know a bit more about exactly what is happening. From looking at (Googling) other cases with this error it is possible something at BT went wrong, so it may be useful for you to check in any BT email user forums to see if others have the same issue.

new messages are downloading to my inbox but can't be read as i keep getting : The RETR command did not succeed. Error retrieving a message. Mail server mail.btinternet.com responded: no such message.

Hi There, Also Bt has been informed and they don't know what to do either. Thanks Mark

Another possible approach - sometimes one message causes this blockage, and all later emails can't download because of the one corrupted or oversize one. However from the BT error - 'no such message' - that implies there is a message Thunderbird thinks exists but BT does not have it. Someone smarter than me might have a suggestion for how to clear the Thunderbird record of downloaded message headers. Are you using POP or IMAP?

Hi There, I am using POP i have looked everywhere to find out if there something jamming it to no avail if this helps. Thanks Mark Ps. Thanks for helping

Hi There, I tried to upload a picture but it said it was too big so i made it smaller, hope this helps in anyway. Thanks again Mark