Hi R C-R,
You might find this interesting. An IP address doesn't always tell you where the hosting server is located. When I first started my business, I used 1&1, namely because they were the cheapest I found at the time. While I had no issues using them to host my web site, I couldn't send emails to my two main clients. They kept getting rejected.
Turned out 1&1's IP addresses are leased to them by their German parent company. So even though 1&1's servers are on the east coast of the U.S., an IP trace declares them as being in Germany. A lot of spam comes from that particular range, so my clients had set their mail servers to block anything from there.
I had to switch to a web hosting company that was not only in the U.S., but had their own servers and local IP addresses.