Multiple, separate domains email server

Hi to All @giacomo @filippo_carletti @alefattorini @GG_jr @davidep !

Those Solution was for 2.3.8 branch

for 3.0.1 branch it is more simple:

--- /etc/e-smith/templates/sogo-config/20user_source_ldap       2015-10-05 17:11:52.000000000 +0300
+++ ./20user_source_ldap        2016-02-16 02:51:53.036406615 +0200
@@ -8,8 +8,9 @@
            id = users;
            type = ldap;
            CNFieldName = cn;
-           IDFieldName = uid;
+           IDFieldName = mail;
            UIDFieldName = uid;
+           bindFields = (mail);
            canAuthenticate = YES;
            bindDN = "cn=sogo,dc=directory,dc=nh";
            bindPassword = "$ldapPassword";