How to GMAIL OSINT like a boss
I will explain a method to find the userId from a gmail address.
With this method you don't need API keys, just your gmail account. It's the easiest method in the entire world.
If you have a gmail address you can find information of the user in another Google Services (Maps, Youtube, etc.)
First we need our sample or target gmail address, in this case I'll use is Sergey Brin's (Google's co founder): sergey.brin@google.com
- We need to compose an email to sergey.brin@google.com
Then we need to go to 'Inspect' (in Chrome with CONTROL + SHIFT + I ) or 'Inspect Element' (in Firefox, using the Right click and the letter Q)
While there, we need to check that the column 'domain' is enabled. Now we need to filter by the word contacts.
Now we go back to the compose screen and click in the email account itself. (The request may trigger before but it always happens while clicking the to email address.
Then if we click in the request we will see:
The id we found is 111627209495762463002. This is the userid related to sergey.brin@google.com
Let's try the id with some Google services:
Bad luck no reviews or photos were uploaded.
- Google Photos
https://get.google.com/albumarchive/100648764407449034381
Let me get a better screenshot.
Services that didn't work
Youtube, I couldn't find a way to user the userid on the urls. I did try:
https://www.youtube.com/feeds/videos.xml?user=
https://www.youtube.com/feeds/videos.xml?userid=
With no results, if you find a way, please let me know. I will pay you $100 dollars but I can only give it to you in person.
Conclusions
I tried the same method with my account and friends and it works consistently.
It's easier and faster than using an API
You could also use it to validate a gmail account. When it doesn't exist, you don't get an id.
Sources
