There is no list of LDAP attributes for an account since it changes depending on what has been done on that account or what is enabled. For instance the zimbraPasswordMustChange attribute is only created in LDAP when you click that box in the admin UI...before then it doesn't exist.
I personally use an LDAP browser to actually view the LDAP on the itself...you will need the root LDAP password as well as modifying your Zimbra LDAP configuration to even allow connections if you wanted to do this, however unless you have a specific need to do this it is not recommended.
Code:
zmprov ga account@domain.tld
actually gives you all options stored for that user, about half of which don't reside in the LDAP directory, so if all you are doing is reading account attributes the zmprov command is probably a better program to use.