Issues with Openmailbox IMAP server

Hi there,

Could you check if there is any reason why my Icedove v38.4.0 rejects 
connecting to the IMAP server of Openmailbox? If I have knocked to the 
wrong door, I apologize in advance.

There's a detailed thread explaining the issue here 
https://forum.openmailbox.org/viewtopic.php?pid=6138#p6138
Some people have reported that downgrading icedove (does it imply a 
libnss downgrade?) solves the problem.

My main query to you is if there's any weak encryption on Openmailbox 
server that icedove is blocking for security reasons, as it could be 
dangerous to advice a downgrade to everyone that is having this problem, 
while the error would be server-side.

Thank you very much,
Elkon