[exim] how to accept mail with invalid to-header?

Hello,

one of our customers send mail with invalid to-headers in the form of

T To: <recpt name<recpt.name@???>

Exim rejects them with: rejected after DATA: "@" or "." expected after "recpt": failing address in "To:" header is: <recpt name<recpt.name@???>

Is there some way to make exim accept mails with this faulty header from that one domain?

Thanks in advance,

Anja