here is some example output from dummy email account attempted to connect my mail client to[*server [*user jms [*server [*pass justin [*server [*user jms [*server [*pass test you can see that my mail client is attempting to log in to the server at and sending the plain text credentials over the wire this is really simple example of how you can take scapy sniffing script and turn it into useful tool during penetration tests sniffing your own traffic might be funbut it' always better to sniff with friendso let' take look at how you can perform an arp poisoning attack to sniff the traffic of target machine on the same network