[Exim] Spammer / Prohibiting single sender-address

Dear Folks,

I know RTFM oder searching the Archive may help me too but I need
a quick solution to prevent Exim accepting an Email in a SMTP
session that has a MAIL FROM with a specific sender address.

Anyone,please?

Have a nice weekend, y'all!

Regards,
Sascha

 ---
 Sascha E. Pollok
 Network Operations / Internet Port Hamburg
 Grosse Reichenstrasse 27
 D-20457 Hamburg
 Germany
 Tel.  +49 40 37 49 19-4
       +49 172 411 78 62
 Fax   +49 40 37 49 19-29
 Email sp@???