How to extract an ip from an email from the remote computer?

Select the email in your email client's inbox and view its Properties.
In most email clients you only have to right click on an email and select "Properties" from the menu that pops up.

Step 2:

You will see a screen similar to the one below (this is from Outlook). Click on the "Details" tab (if using Outlook) to view the email's headers (shown below).

Step 3:

You will be looking for the bottom most "Received: from" entry in the email header. In this example the desired data is highlighted. This entry signifies who sent the email, and will contain the sender's IP address.

Step 4:

The sender's IP address is highlighted below. It will be the only 4 field number in brackets (i.e.: [xxx.xxx.xxx.xxx]). If SpyAnywhere is running on the sender's computer you can paste this IP into your browser to connect to it.