[Semibug] sendmail question

[Mike Wayne]

I'm getting messages like this on a FreeBSD server in /var/log/messages
   sm-mta[81517]: 01CKJqXB081517: SYSERR(root): hash map "helo": missing map file /etc/mail/blockhelo.db: No such file or directory

Google is NOT finding anything about blockhelo
grep helo /etc/mail/*					finds nothing
strings `which sendmail` | grep helo			finds nothing
grep blockhelo /usr/src/contrib/sendmail/src/*		finds nothing

Clearly, it's a database of some sort, likely used by sendmail.
Any pointers of where to look?