Someone using the server with an IP address 218.252.135.146 is
illegally using my email address to send spam. What can I do to stop
this? Do I have any legal recourse in the US?

What rotten luck, jjdon! You have my deepest sympathies.

Here are some recommendations for damage control:

#1:
If you haven?t already, contact your ISP/e-mail provider(s)
IMMEDIATELY. Let them know what's been happening, so they don't cancel
your service and blacklist you if they start getting complaints from
the spam victims.

#2
A Drastic move, but is probably going to be necessary: Obtain a fresh,
new e-mail address. It is likely that some spam victims, not realizing
that the e-mail address they received was "spoofed", will report your
e-mail address to their ISPs and Spam Blacklist organizations. You may
find that e-mails that you legitimately send from your spoofed address
will be rejected by certain ISPs who use blacklists to block spam, and
you will not be able to communicate with people who do want to hear
from you.

As your last act in the e-mail account under the old name, send a
message to everyone with whom you wish to maintain contact, telling
them your new e-mail address, and asking them to delete your old
address and add the new one to their Address Book / Contacts List, so
that messages from you at the new address don?t get bounced or just
thrown away. "cc" yourself on this message at your new e-mail address,
so that you can hopefully just set up a whole new Contacts list there
in one fell swoop.

#3
With your new e-mail address account: If the functionality is
available, set up e-mail filters to cut down on the spam you receive.
Delete any junk mail that comes to this address. Do NOT bother trying
to "unsubscribe" from any of it; this frequently just confirms the
validity of your address and can lead to having your address placed on
a list that gets sold to thousands of spammers.

#4
Avoid using your new e-mail address to post to Usenet groups and other
web forums. If you wish to post on these sites, obtain a "throwaway"
address at a site such as http://www.hotmail.com or
http://mail.yahoo.com , and use that address to make your postings. Be
sure to login in at least twice a month and delete any junk mail, to
avoid having your "throwaway" mailbox terminated due to inactivity.

#5
Report the offending IP Address to Spam Blacklists:
http://directory.google.com/Top/Computers/Internet/Abuse/Spam/Blacklists

#6
File a Complaint with the Federal Trade Commission, under whose
purview Internet Commerce and Spam fall. Be sure to include the ISP,
any headers and other information which was contained in the spam, and
anything else that you know about the spammer. While I wouldn't expect
results from this avenue, you never know -- if they get lots of
complaints about this particular spammer, they may do something about
it.
http://www.ftc.gov/spam

#7
If you are in the U.S., contact your Federal and State legislators
urging them to pass more extensive laws to prevent spamming and punish
spammers.

How to find your US Senators:
http://www.senate.gov/general/contact_information/senators_cfm.cfm
How to find your US Representatives:
http://clerk.house.gov/members
How to find your State Legislators:
http://www.firstgov.gov/Agencies/State_and_Tribal.shtml

If you live in another country, I still urge you to contact your
governmental representatives there.

Before Rating my Answer, if you have any questions about the above
information, please post a Request for Clarification, and I will be
glad to see what I can do for you.
 
Best wishes! 
 
aceresearcher

jjdon,

Oddly, everything you've described is explicitly illegal, which one
would think enough to bring suit against the spammer in question. 
However, it might not be so easy...

The 2003 CAN-SPAM Act gives a lot of footroom for lawsuits to be
brought against spammers, both for the act itself and for the fraud
usually involved in it.  Section 4.a.3 of the bill reads "Whoever, in
or affecting interstate or foreign commerce, knowingly materially
falsifies header information in multiple commercial electronic mail
messages and intentionally initiates the transmission of such
messages, or conspires to do so, shall be punished as provided in
subsection (b)".  Subsection B calls for up to 5 years in prison and
big fines, depending on the severity of the case and any other felony
involvement in the crime.  However, this doesn't work quite as
linearly as other sections of law: you yourself can't run down to the
DA's office with an IP address in hand and demand that they take
immediate action.  All cases that have been brought against apammers
so far have been against some of the worst offenders, and don't seem
to follow any particular pattern, other than prosecutors who are out
to test the strength of the bill.  So, while the spammers are in
violation of the law, I'm not sure just how much you can do about it. 
Sorry... you can probably still talk to someone with more legal
authority than myself, to see if any DA in your area is planning any
suits, and if so, you can probably try to get your spammer's name
added to the list.

Complicating things slightly is the problem of tracking down who
you're actually dealing with... if you've managed to track the spoofed
IP, I suspect you have some degree of tech savvy, at which point I'd
be willing to bet you know that IP's aren't concrete (especially if
it's a dynamic IP), and you would need to find more evidence against
the party in question in order to prosecute.

Good luck, I hope you manage to bring down fire & brimstone upon his
head, so that we can all stop getting a dozen 419 scams a day...

-- bananarchy-ga

That shows up as a cable modem in Hong Kong (cm218-252-135-146.hkcable.com.hk)

Complicating the matter is the taking over of innocent computers for
sending spam.  So, sometimes you don't know if they are personally
involved in the it.  It looks like that network is popular for sending
out spam.

http://groups.google.com/groups?num=100&hl=en&lr=&ie=UTF-8&safe=off&q=hkcable.com.hk

Your best bet is going against the company they are advertising. 
Better than 95% chance they are involved in the spamming.

You can file a complaint here if interested.  Most of the time the
government doesn't do much unless money (read $5K+) is involved. 
Maybe that will change.
http://www.ftc.gov/spam/

Even worse than sending out spam, my email address has been used to
send out viruses.  That can be worth tracking down because it is
likely someone you know.

ulu-ga,

If you don't mind my asking, how did you figure out that 

218.252.135.146

is the same as 

a cable modem in Hong Kong (cm218-252-135-146.hkcable.com.hk)


I'm always on the lookout for good lookup tools.


pafalafa-ga

Aha! You pinged it!

Some computers might have a firewall that block a ping so I used:

Reverse DNS Lookup
http://remote.12dt.com/rns/


I've still have the same email address that I had 20 years ago.

Unfortunately, I do get some spam because of prior posts to newsgroups
and groups which have listed email addresses on webpages.  I have
considered having an address with the year on the end so I can peel
off the spammers with the new year.  I also have my own domain that I
code the username to stand for whomever gets it.  Then, if I start
getting spam to that address, I can track down the source or just
filter it into the trash.  That idea came from someone who used their
middle initial to code it for junk mail.  Remember when people
complained about that instead of spam?

also, check www.arin.net (whois) to find out who the ISP holding the
IP address is, then send an email to abuse@isp and let them also know
what's going on.