Sometimes you may find that you are unable to send mails and will find the following lines in your exim mainlog:
2009-04-05 19:08:41 H=[xx.xx.xx.xx] temporarily rejected connection in ?connect? ACL: ratelimit database not available
The exim cache database might be corrupted.
You need to delete the following files :
You can do as follows :
rm -fv /var/spool/exim/db/*
and then restart exim :
service exim restart