What is mail forwarding?

So if I understand correctly, it means that the sender of the email could have also sent it to others

for example, to other people and then to me?

To locate the IP, I copied the full header of the email that I put on rezo tools in the email header.

And it gives me 3 IP addresses

one which is a loop apparently, one which is that of Google in the USA, and one which is private

because I would like to locate the IP of a gmail.com address

thank you for your help and your reply

Yes, that's exactly it regarding the forwarded email.

As for the IP address, I suppose it depends on the email service you're using. Generally, you need to view the email header, display the sources, and find a line where it says Originating-IP or something like that.

I have already looked in the header.

And there is no originating IP.

I have it in my main email but not on my laposte.net account.

What are my options?

Thank you in advance.

If Laposte doesn't allow you to see the header, you can just forward (FW, precisely ^^) it to your other address and check the email header: you'll see your own IP address since you forwarded the email and the IP address of the original sender. That's all ^^

So I just did it and it shows my IP and another IP which is Google's in the United States.

Because the address I'm trying to test is a Gmail address.

Do I have any other alternatives?

Thanks in advance for your help.

In fact (and I didn't know this, you taught me something ;) ), we can't find the IP address of a Gmail.
See: https://support.google.com/mail/answer/7039474?hl=fr&visit_id=637166011265947701-1321123794&rd=1

Unless of course you ask Google, but I can't guarantee the result.

Thank you anyway, and I'm glad you learned something new thanks to me.

You're welcome! I hope you have a clearer idea now ;)