Connection to the server is ok , but nodownloading of the messages, sending is ok
With Orange only, as the second account I have works correctly: When connecting to receive messages, the usual message appear: " téléchargement du message 1 of* ", but nothing happend. I can send messages, even from Orange account to the other one. The reception of the messages on the Internet orange mail is ok. Some times connecting I got this error message: "mail box is locked by Pop server"
Alle antwurden (1)
https://support.mozilla.org/en-US/kb/problems-sending-and-receiving-messages
You may also try to increase the interval you check for new messages.