Postfix/Maildrop and too many connections issues

We have a system set up whereby postfix and maildrop gather user info
from a pg database (7.4.2 on FreeBSD 5.2.1) to do local mail acceptance
and delivery. I have configured max connections at 512 but I find that
this is not enough and I get "connection limit exceeded for
non-superusers" errors. I see upon ps ax that there are hundreds of idle
connections (state I).

Is there any way on the server end to close these connections (the
process is apparently for postfix and then maildrop to open a
connection, run one select statement, and supposedly close the
connection). If not, would pgpool help in this case? Since all the
connections are basically 2 users (one for the mail delivery system and
another for the mail retrieval), are there any such "connections"
limitation by pgpool (i.e. if we get a spike of 700-1000 queries each
with their own "connection")?

Thanks,

Sven