rebuilding exim with gdbm instead of BDB solved the problem... but it
looks strange to me, because I do not have BDBv3 installed on my
system...
bash-2.05b# pkg_info | grep db
db41-4.1.25_1 The Berkeley DB package, revision 4.1
gdbm-1.8.3_1 The GNU database manager
:: Mikhail Lukyanchenko :: spider@??? ::