I once fooled by a paypal phishing email. I thought the email sent to me was authentic. I only realized that it was scam when I noticed that the URL of the PayPal page that I was logging into was not the authentic URL of Paypal.
Then there was a time that GMail tried to save its users from scammers or phishers by rejecting emails that are supposed to be coming from paypal or ebay but did are not actually coming from paypal.com or ebay.com domains.
Now, GMail continues its efforts to protects its users from ebay and paypal phishers.
This time Gmail uses the DKIM or Domain Keys Identified Mail technology. To enable this feature, just go to the settings > Labs tab. Click enable next to “Authentication icon for verified senders” and then click on Save changes button.
After that, every time an authenticated email coming from ebay or paypal, you’ll notice the key icon as shown on the image below:
So, it will be easy for you to identify authentic emails from ebay and paypal.