Zimbra Desktop and KeePass

I had my hotmail account set up in Zimbra and everything was fine until I changed my hotmail password to a password generated by KeePass password safe. The next time I opened Zimbra it asked me for the new password, I pasted it into the box but it wouldn't save, the save box was greyed out. I tried editing the account settings but got an authentication failed error, once again it was the same problem, it didn't accept the new password.

When I went to hotmail directly the new password worked fine. So I would be interested to know why I can't change the password in Zimbra. Thanks in advance.

Tried again with a shorter, albeit not as secure password and it worked. I'm assuming there are rules for length and composition of passwords for Zimbra but I can't seem to find any specific info , perhaps someone could help me with that.