Sendmail error

I am seeing this in the rt.log:
/usr/sbin/sendmail exited with status 17152

Have pinned this down to an invalid email address in the to or cc
line… Seems when this happens, the person submitting the ticket gets
an email saying the ticket was created, but when trying to view the
ticket, it returns bogus ticket. Is there a way to inform the user the
ticket create failed due to bad email address?