I use one folder called customers then 26 subfolders (A,B,C etc) then one sub-sub folder for each customer (eg 20 under the letter A, 26 under the letter B etc). I can see them all on the webmail. Last night I could see them all on T'bird. This morning I can see the A,B,C etc folders but none of the sub sub folders. The subscribe page can also see the A,B,C .... folders but cannot see that there are sub folders below these so I cannot re-subscribe to the individual customer folders. The whole thing is an IMAP setup on Exchange server. Fasthosts have spent three hours on it this morning and canot replicate the problem. I am using T'bird version 45.1.1

Any suggestions would be very welcome.