Look at the bottom right hand side of the page when you're logged into Gmail. You can see "Last account activity: xx minutes ago Details". Click on the "Details" link to get a list of IP address and locations of access to your account.
According to the documentation, they may include the sender IP.
IP addresses can be considered sensitive information. As such, Gmail may hide sender IP address information from outgoing mail headers in some circumstances.
I've experimented with it a bit, and I think it works like this:
For generic gmail addresses (@gmail.com, @googlemail.com), gmail ...
Those Washington State and California IP addresses are the address of Yahoo's and Live's mail servers. The sender's IP is not included in the email for privacy and security reasons.
Why are you trying to find the IP? Is there another way to achieve your goal beside with the IP?
I don't think the IP address data was meant to be displayable. It might only facilitate Google in providing better search results and resolving account security issues. It might be possible that the takeout data contains such information, I cannot confirm this at the moment.
Meanwhile the Activity Information tab of Gmail does display IP address of ...
To track the IP who used your Google Account:
Go to the Account after clicking on the icon at the top right
corner of Google account and then move to the Devices option
under the Recent activity.
Now you can click on the Manage all devices connected to your Google account which would show the devices using the Google ...