Can originating IP addresses be faked?

[David Fletcher]

Thanks for all the advice.

Sounds like it's going to be either compromised computers on the ISP's
network or an ISP that doesn't care so I'm going to continue doing as I
am.

When I get spam I generally just block the entire range of addresses
which is working nicely for addresses such as 171.248.164.38 which is
somewhere in Vietnam and repeatedly gets blocked. Others are in Turkey,
Brazil and Georgia, USA.

It's a while since I last had spam from a UK address so maybe ISPs here
do care. Interestingly, all of the banking scam email I've received
lately appears to originate in the Netherlands.

Dave