Can't Send Empty Message

[Rodney Barnett]

I tried to subscribe to another horde mailing list by sending an empty message
(following the instructions at http://www.horde.org/mail/) using the latest IMP
from CVS and I got the message "There was an error sending your message" in the
compose window.  I found that adding a single space is sufficient to have the
message be sent.

Looking at compose.php, it appears that this is expected behavior.  If that
continues to be the case, it would be nice if the error message was more
informative.  However, it's occassionally useful to send an empty message.  Is
it necessary to prevent this?

Rodney