Memory leak?

[Jeffrey Ross]

I believe I have a memory leak someplace on the system,  over several 
days I watch the used memory slowly climb and eventually the system 
starts swapping, the application load has not changed.  I have tried 
stopping processes and restarting them in the hopes that the memory 
would be returned to the system but no such luck.

The system is Fedora Core 4, the main applications on the system are:

mailman 2.1.7 (built from sources)
exim 4.60 (built from sources)
spamassassin 3.10 (built from sources)
named 9.3.2 (built from sources)

everything else was installed via yum and is the most current install 
available from the FC repositories.

These programs are:
apache 2.0.54
postgresql 8.0.6 (used for exim's databases only)
perl 5.8.6
python 2.4.1
imap/popd version ??
sshd (Open SSH) 4.2P1
Kernel 2.4.16-1
How can I track down the source of the memory leak?

according to "top" spamd (spamassassin) is the largest consumer of 
memory, however it seems to stay pretty stable compaired to how fast 
memory usage is climbing

TIA, Jeff