[imp] Redirecting failed error...

[Anant S Athavale]

Dear members,

I have set up two systems.  One system runs http and ldap. The second one runs
cyrus imap and postfix services.

The one which runs HTTP and LDAP has following configuration.

OS. - Redhat 9.
Apache : 2.0.40
PHP: 4.2.2.0 downloaded from ftp.horde.org for redhat9

Horde 2.1
IMP 3.1


The one which runs cyrus-imap and postfix is 

OS: Redhat 7.2


When I try to redirect an email, I get the following error on display :
Redirecting Failed.

And in horde.log:

error: unable to set sender to [cyrus at abc.ernet.in] 
Return Path: <root at isac.ernet.in>
[on line 708 of compose.php]

This error did not used to come when HTTP and LDAP were being served from the
second system itself.

We had to migrate HTTP and LDAP services to another system to avoid the load 
on the single server.

Please let me know, if any of you have experienced such problems and sorted out.

Regards,
Anant.