[exim-dev] Stop sending out emails when having SMTP error co…

Hi Exim Dev,

I'm setting with exim.conf and wondering if I could set Exim to stop
sending out email with specific domains and IP?
Example:
When I send emails to Yahoo server with IP 1.1.1.1, it says: 421 Service
unavailable.
How do I config Exim to stop sending out with IP 1.1.1.1 and domain:
yahoo.com?

Thank you so much!