OT: Do RBLs take precedence over access entries

[Steve Campbell]

Does anyone know which takes precedence in sendmail: RBLs defined in 
sendmail.mc or the access file?

I'm having a time with one customer who's domain uses a mail service or 
ISP that sends quite a bit of spam. I've blocked quite a bit of IPs in 
access, and some are more than likely ones the senders outgoing server 
is apart of, but see that a few of their IPs are listed in spamhaus 
also, which I use in sendmail (not MS). I've added an entry at the top 
of the access file to "OK" the sender, but the email still gets blocked.

I've informed the sender that she should be receiving some form of 
notice that we have rejected their email, but they insist that they do 
not get the notice, so I'm having a little trouble figuring out which IP 
they're using this week.

Thanks for any help.

steve campbell