Better support for multidomains hosts/servers

[nobody]

RC would have an enhanced "domain" field in the login
form, which may be populated form a config array or a
mysql table, so that the users dont have to write
username@domain il the login field. It is useful for
multi domains hosts.

For now, you can write this in your main conf : 
$rcmail_config['default_host'] =
     array("slashdot.org","microsoft.com");

But this is a "server" field, so in this example, you
get a pulldown menu with "slashdot.org" and
"microsoft.com" and if I enter "myname" in the login
field, RC will try to authenticate myname@slashdot.org
by connecting to host "slashdot.org".

OK in many situations that is fine. However, in my
architecture, the server resolved as "mydomain.com" is
not the imap server and cannot be it.
I suggest an array, or a mysql table, with 3 (or 4)
fields "display_name", "domain", "host" (and maybe
"port"). 
So in the login form (in the server/domain form field)
you can :
- show the "display_name" (for example showing "DELL
France" instead of "fr.dell.com") 
- concatene the imap login  by adding the "domain"
field to the RC login field.
- and finally connect to the "host" field (i.e.
mail458.dijon.fr.dell.com, and maybe on "port" port) to
make the request.

I hope i was clear enough because I'm not very good at
explaining things. Here is another explanation if
necessary :

Lets say I use $rcmail_config['default_host'] =
array("slashdot.org","microsoft.com "); in my config file.
I login as :
login : myname
pass : mypass
server : slashdot.org

From what I see, RC connects to the host "slashdot.org"
on port 143, asking for LOG1 LOGIN myname@slashdot.org
mypass .
I hope you are OK with that, otherwise I misunderstood
something.

Now lets say the host "slashdot.org" is the dedicated
web server, and the imap server is "imap.slashdot.org".
Now we have a problem because RC will try to connect to
the web server instead of the imap server. And if you
enter "imap.slashdot.org" in the
$rcmail_config['default_host'] array, OK it will
connect to imap.slashdot.org, but asking for LOG1 LOGIN
myname@imap.slashdot.org mypass.
If not, explain me what i am wrong

[thomasb]

This feature is available with the 'username_domain' config parameter.