To obtain the IP address from which an email originated, users can check the message headers. In Outlook, this can be done by opening the message, selecting the "View" menu, and then "Options" to access the Internet Headers. However, it's important to note that this information can be easily spoofed, meaning the displayed IP address may not be reliable. Attackers can manipulate headers, making it appear as though the email came from a different source. While SPF DNS entries can help verify the authenticity of the sender, they are optional and require access to the DNS records of all mail servers involved in the email's delivery. For webmail users, the process varies by service, and they should look for options like "Show Details" or "Show Original" to find header information.