This is an old revision of the document!
Starting January 2026, this is not possible any more.
You have to remove forwarding for ULCN mail yourself if you set this up previously. You can do this by accessing the WEBmail frontend at https://webmail.campus.leidenuniv.nl
A ISSC helpdesk information page is (used to be?) available in the ISSC helpdesk.
Anyway, we have made available these instruction directly in this PDF.