I am using spark for IM using Zimbra Acoount.
this is in brief like.
username :- zimbra user name without domain like user1
password :- Users' password
Server :- Use only domain (please don't use Server name or IP)
only domain like example.com of
user1@example.com
Go to Advanced tab
uncheck the :- Automatically discover host & port.
then,
Host :- your mail Server like mail.example.com
port :- 5222
Hope it's help you
