Admin Tool to Send Me Email

We have been using PostgreSQL on Mac OS X for about a year now. Ongoing
monitoring has proven very easy because the DBMS engine is so reliable, and
mostly I use phpPgAdmin, an extremely useful tool. However, its worth my
while to make it even easier. I would like a tool that would send an email
whenever an error message is generated, such as messages from SQL class 53
(53100 disk full, 53200 out of memory, 53300 too many connections), class 57
operator intervention, class 58 system error, and a few others.

I looked for such a free tool on pgFoundry, Gborg, and postgresql.org's
Downloads page but didn't see anything like it. If you know of one, I would
really appreciate it if you provided the web site. Thank you!