Share your experience!
where do I install the certificate for an exchange active sync synchronisation ?
can find anything in the manauals
You don't need to.
When you setup a new exchange account you just tic the "Allow all SSL-certificates" box. Should be that simple. Have you tried this?
I'm not sure ... the system continues to refuse my login .
still in doubt what kind of login name I should use ...
Ah, I see. That's hard for me to tell though. Have you checked with the server admin about this?
For my Exchange mail here at work I have the same user name as the one I have when I log in on my computer. Maybe that helps? 
I am also facing the same issue...for my webmail server....its showing invalid username/password..
while I being out of my home network ... password validation is correct.
When coming inside into the network .... password credentials are false
any difference , server has an internal and an external name, and that means 2 certificates .
cejcked out the mac address and even that one is identical .. so it is the same server and you see the invalid login message in the journal
funny and frustrating.