I found the fall range of Orange servers, they have no reverse DNS so I guess thats why Avast adds the IP instead of the Hostname in avast SSL accounts.
(193.252.22.189, 193.252.22.134, 193.252.22.138, 193.252.22.140, 193.252.22.187, 193.252.22.139, 193.252.22.188).
But now the problem is that when a server is busy, Avast mail shield wont move on to another server and just times out in thunderbird. With Avast mail shield off, thunderbird instantly moves on to another server if busy and doesn't time out.