restarting courier opens exim4 relay

[vadik <vadik@kutsyy.com>]

I would appreciate some insight on this.

I run exim/procmail/courier combination but I am not using smtp for 
outmail.  With courier I use courier-imap-ssl and I have mozilla 
connection to 6 accounts at the same time, so my MAXPERIP=40.  
Yesterday, I started to have "server disconnect" errors, but restarting 
courier (courier-authdaemon , courier-imap, courier-imap-ssl, 
courier-pop and courier-pop-ssl) fixed the problem. Later I noticed 
unusual activity on exim, and after some pocking around, I found that 
exim relay was fully open, and some one was sending spam.  Restarting 
exim4 fixed open relay problem.

Today happened exactly the same (this time I checked for open relay).

I don't really know where to begin looking in to this.

Thanks,