[imp] IMP/HEAD: Default Identity set to "<username>@" without FQHN?

[Greg Earle]

I'm using Horde and IMP from CVS snapshots of March 4th (yeah, I
know, a few weeks old now ... )

I just installed/configured everything on my production server,
and immediately a co-worker found a problem - the "Default Identity"
as shown in the "Identity" field doing a "Compose" only shows up as
"<username>@", instead of the expected "<username>@mailhost.my.do.main".

I don't understand why - I have "maildomain" set in the "servers.php"
file, and I don't have any "from" hooks.  (I saw a post from Jan
that said if there were no "from" hooks, then IMP would get the
information for the Default Identity from the "maildomain" setting.)
Well, mine's in there and it's set, but I still get "<username>@"
for the Identity value.

What am I doing wrong?

In searching through the list archives via Google, I found a patch
from someone that auto-referred you to the Identities page if the
"from_addr" variable was empty.  While that's a neat hack, I'd
rather not have users presented with such a confusing screen upon
their very first interaction with IMP.

Also, I've seen references to "locking" prefs in config/prefs.php.
If I can't fix why I'm getting "<username>@" instead of getting
"<username>@mailhost.my.do.main", what will happen if I change
the default

// user preferred email address for From: line
$_prefs['from_addr'] = array(
     'value' => '',
     'locked' => false,
     'shared' => true,
     'type' => 'implicit');

to (presumably this is what is meant by locking)

// user preferred email address for From: line
$_prefs['from_addr'] = array(
     'value' => 'mailhost.my.do.main',
     'locked' => true,
     'shared' => true,
     'type' => 'implicit');

???

Thanks,

	- Greg