[lug] Monitor Email

[jd]

Hello,
 A client of mine has asked if I can set up a way
for him to monitor email. He actually wants to see 
the content. So, I have tried using.. (on the Linux firewall/gateway)

 tcpdump -X  tcp port 110
 
as well as snort and ettercap. None of the above really presents the
email in a *readable* format. Just decoded packets with the ascii
contents but, lots of other data too that makes it hard to see
the email *content*.

Could someone suggest a program that could help
that runs on Linux. Or maybe make a suggestion on 
a way to parse with perl the output of the tcpdump
command.

Thanks,
jd