I replace the design of a notes mail database V.4.5 to 8.5. The problem is, the folders are not there. Is there any specific to do to get the folders also ?
try upgrading to inotes6.ntf template and then to mail85.ntf.
Upgrading from a version below 6.5.1 to 8.5 isn't supported. Don't forget to check "Upgrade folder design" (and make a backup of course ;) ) when replacing design.
There is a special action to upgrade the folders. A default "replace design", will not replace the design of folders made by the users.
I think it's under "Actions"->"Folders"->"Upgrade folder design"
I think the problem here is that Notes 4.5 didn´t have folder as it used categories. So you need to use the console command to convert the categories to folder.
For a normal Domino 8.0 to 8.5 conversion the following will work (for all mailfiles in the folder MAIL):
lo convert -u mail\ * mail85.ntf
In you case I would try (-c = Converts categories to folders):
lo convert -c mail\ * mail85.ntf
I would try it with a mailfile copy at first:
lo convert -c mail\mailfilecopy.nsf * mail85.ntf