[imp] Problem with redirect.php

[CREMER Franck]

Hi,
I use IMP 3.0,
When i use it in local network, it work fine.
But when i tried to used it from internet, i have the login page http://mail.adef-asso.com/horde/imp.
And when i logged my user, i obtain th link: http://mail.adef-asso.com/horde/imp/redirect.php?Horde=8fb2027cfebe22284e1b11f074ace004
and the message: server not found or dns error.
In the past i used IMP 2.0 and it worked fine.
What is the problem?
 
franck