MailScanner + Exim4 : Using local blacklists

[Pete]

Hello all,

I've just started using MailScanner on my Debian Etch server. Aside from a
few necessary tweaks I more or less left the defaults alone, and am very
happy with the overall set up.

I do have one very dumb question to ask though; Will my exim4 server still
read (for example) /etc/exim4/local_sender_blacklist *before* MailScanner
starts work on a message ?

I ask this as senders/domains in the aformentioned blacklist are normally
rejected at RCPT TO: time during the SMTP connection by Exim.

Using a local telnet session to port 25 on my server, I submitted a message
using one of the domains I have blacklisted, and it was accepted.
Previously, exim would have permanently rejected that message.

What have I messed up/forgotten to do ?

I'm thinking now that I have to set up a ruleset in MailScanner to reject
hosts/senders/domains now. Is this correct ?

Thanks for your time all.

Regards,

Pete.