it most likely do not need a restart of the server, but of the connector and possibly samba:
# service univention-s4-connector restart
# service samba restart
I am not sure if there is a mapping of the telephone number already included (I doubt that), but the mail address should map to primarymailaddress. If you have further mail attributes, you would need to create extended attributes at the UCS and map them to the AD. That is certainly possible, but i would (as I said) recommend a consulting.