THINGS NEED TO KEEP IN MIND FOR SECURING / AVOIDING SCAMS*
The importance of knowing whether your account comes with the Original Email has to do with when you need to get support from Steam for your account. If there are no purchases on your account, Steam will relegate and assume that the person emailing them using the Original Email, is indeed the original owner.
Payment data is most important evidence someone can have when contacting Steam support, followed by using the original email account.
If you are purchasing an account with Steam market history, make sure the seller is reputable as the Steam Market purchase history evidence will trump the original email.
Credits: EpicNpc

“ORIGINAL EMAIL” OGE STEAM
“ORIGINAL EMAIL” FILTER – HOW TO DETERMINE IF THE EMAIL HAS BEEN CHANGED
A new “Original Email” filter has been added to the CSGO Account forum. This filter can help buyers find accounts where the seller has full access to the original email that was used to create the Steam account.
In order to claim your account comes with the Original Email, you must show proof of one of the following.
Show the “First Letter” that Steam sent when you first registered your account and compare the date with the account creation date.
Or have emails from Steam with dates that line up with the first games played on Dota 2, CS:GO or any other steam game that has recorded games played with dates.
Methods to find out the creation date:
- If an account is over a year old, you can look at the “years of service” badge to get the exact creation date.
- If not, look at the other badges. The 1+ game and pillar of community badges are usually earned on the day of creation or shortly after.
- The “Licenses and product key activation” shows all games activated on the account, including the free ones. The first game usually matches the creation date.
A “First Letter” from Steam will look like this: