send mail to multiple recipients

["S.T. Wong" <st@hp735c.csc.cuhk.edu.hk>]

Hi there,

I'm using OpenLDAP 1.2.3 and sendmail 8.9.3 on Solaris 2.6.  We use 
mailacceptinggeneralid as the search criteria and returns maildrop as the 
destination.  When there're multiple matches in mailacceptingeneralid, and/or 
multi-valued maildrop is returned, the resulting recipient address will be a
list of comma-separated maildrops of all entries found.   

I see something like this in sendmail log, e.g. :

to=<address1@abc.com,address2@efg.com,address3@xyz.com>

and the mail was delivered to xyz.com only which complaint about user unknown.

I'd like to know if it's correct behaviour for multiple matches/recipents. 
Besides, is it possible to return to sender for multiple matches with warning 
messages instead sending the mail ?

Would anyone please help ?

Thanks a lot.
Regards,
ST Wong (st-wong@cuhk.edu.hk)