[exim] Must $home be prepended to relative directories in Ex…

I'm a bit disappointed that "[w]hile processing an Exim filter, a relative
path such as folder23 is turned into an absolute path if a home directory is
known to the router". That means I can't make use of $address_file in any
meaningful manner, unless I set router_home_directory to "", but that has
other implications, for example that I can't set file = $home/.forward for
the userforward router ($home is usually, but not
necessarily, /home/$local_part).

Now I have to repeat "Maildir/" for every save command. Alternatively I can
use absolute pathnames to refer to the maildir, and let the transport
transform /Foo/Bar into ~/Maildir/.Foo.Bar, but then I can't save mail
outside ~/Maildir, should I wish to do so. Or I could strip off any $home
prefix, but then I can't save mail in any other directory under my home.

$home is not prepended to the arguments of fileinto in Sieve filters. Why does
Exim filters have to be different? One can get the same result by setting the
file and directory options of the appendfile transport.

I request an option!

Also, a to_mod_utf7 string expansion operator would be nice to have to convert
e.g. UTF-8 folder names to the modified UTF-7 encoding used by IMAP servers.

--
Magnus Holmgren
holmgren@???