How to find out someone's IP, can you tell from an email?

Your average user may be able to find an IP address that an email was sent from. And if they type that into the right website (something like http://tools.whois.net/whoisbyip/) it will tell them that IP is currently held by whoever your Internet Service provider.

I looked up my ip (go to whatismyip.com) then go to http://tools.whois.net/whoisbyip/ and put in the IP and you can see what kind of info it gives. Mine says:

OrgName: CenturyTel Internet Holdings, Inc. OrgID: CIH-12 Address: 100 CenturyTel Drive City: Monroe StateProv: LA PostalCode: 71201 Country: US Which just tells you where Century Tel is based at. I’m on the oposit side of the US :P.

As for finding out your name or anything from that IP address, I believe only law enforcement can find that out from an IP, since they would have to get the information from your ISP

They can try to attack your computer with an IP address, but if your behind a router its pretty difficult, or even if you have a have decent fire wall installed on your computer.