Mail sent via webmail can hide a user's IP, but mail sent from a client will include it, so I can ban those.
The issue here is that residential internet users have dynamic IPs, though they may not change for a while, so anyone knowing anything about how their router works can change their IP easily, as can dial-up and some DSL customers just by disconnecting.
Nevertheless, I can get them blocked for you.
Relevant Skills and Experience
I run a web hosting service and have extensive server experience.
Proposed Milestones
£25 GBP - Up to 20 IPs (retrieved from e-mails with full headers) blocked