Good news, your workstation/laptop can resolve hotmail server name.
So, to summarize:
- you can resolve server name
- FW authorizes outgoing connections from internal to internet for the requested ports (995 & 587)
- your client is configured as described in Robb's link
- you are of course using the right login/password
... but it still doesn't work
hmmm, be sure your client's IP matches the one you set in FW
look at /var/log/syslog while trying to open connection from client to hotmail server
have a lso a look at Zentyal FW log (using Zentyal GUI is perhaps easier)