[exim] limiting a number of simultaneous connections per dom…

Hello,

Is there a way to limit the number of simultaneous connections per
domain and not sitewide (for every domain)? I am getting

SMTP error from remote mail server after initial connection: host
mx.poczta.onet.pl [213.180.130.86]: 450-5.7.1 Come again
later\n450-5.7.1 Ask HELP for our contact information.\n450 5.7.1 Too
many simultaneous connections from same IP address (12 max 10)

If it can be done, could the no-more-than-ten-connection domains be
put in a file and looked up while opening new outgoing connections?

Many thanks for your help!

--
Zbigniew Szalbot