[Exim] Spammers ...*.mail.yahoo.com

Hello All,

I am using Exim4 and I really suspect that my server is getting spammed from
something like smtp.mail.yahoo.com and which keeps chaging like
anything.mail.yahoo.com.

How do i configure Exim to Reject all mails from *.mail.yahoo.com, I have
added the entry in /etc/spammers file but since the address changes i am not
able to stop that what should i do?

I want to Reject all mails from *.mail.yahoo.com ?

Please help it will be appreciated.

Regards,
Tina.