How do you get someones IP who emails you with a form?

[EPJS]

I've seen things like "message sent on X date from this IP: X" in email replies to emails I sent others using their forms.

How do I add something like that in my mail form to catch their IP address and print it in the email?

I already log their IP and time elsewhere, I can compair the times an email was sent to me with that log. But this would be more convient since the data would be right there in the email.

[Drakla]

$_SERVER['REMOTE_ADDR']

[MarkR]

People don't have IP addresses, machines have IP addresses. $_SERVER['REMOTE_ADDR'] will contain the IP address of the closest proxy in the chain to the server. This will sometimes be a unique IP address per user, but often won't be.

Mark