[imp] external link to mailbox is shortened (imp 6.0.2)

[Jens Pranaitis]

Hello list,
I'm having some trouble linking to a specific mailbox, with imp 6 (it 
worked with version 5 and below). We have a link in our help documents 
which the user can click to open the Spam folder. The link looks like
https://webmail.phil.hhu.de/horde/imp/dynamic.php?page=mailbox#mbox:SU5CT1guU3BhbXZlcmRhY2h0
"SU5CT1guU3BhbXZlcmRhY2h0" is the name of the maildir ("Spamverdacht") 
and when I switch to the folder in Horde the url is the same. However 
when I follow the external link and login to horde the URL is shortened 
to 
https://webmail.phil.hhu.de/horde/imp/dynamic.php?page=mailbox#mbox:SU5CT1g
This only occurs when I'm not logged in to Horde already, so I assume it 
has something to do with the redirect done by the login page.
Is this expected behaviour? Is there a way to make external links work 
like they did with imp < 6?

Kind regards,
Jens Pranaitis
-- 
IKM-Serviceteam der Philosophischen Fakultät
HHU Düsseldorf
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Tel.: 0211/81-13077