Gmail Error #502: Your Email Was Not Sent (Solved)

A common error message that shows up on Gmail is, “Oops… A Server Error Occurred And Your Email Was Not Sent (error #502 ). This is a major headache for the over 425 million Gmail users around the world. Below we’ll explain how to fix the Gmail Error 502 means and how to solve this issue.
 
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How to Fix Gmail Error 502

• Sign into your Gmail Account
• Select on the Gear Box and choose settings.
• Switch to “Lab” tab under Settings
• Search by typing in “Background send”
• Disable this lab feature.

 
If the same Gmail Error 502 keeps showing up after it has been fixed once already, follow these instructions: 

• Update the web browser
• Clear cache and cookies.
• Disable any browser add-ons/extensions
• Restart the web browser
• Try starting Gmail without any labs by using (https://mail.google.com/mail/?labs=0)
• Temporarily disable your virus checker

 
Another method to fix “Oops… a sever error occurred and your email was not sent. ( error 502 )” is to open a new email and type in the correct email address. Then in the subject add “Re:” and then the subject title, this is a temporary fix to the Gmail Sever Error 502.
 
If these steps did not help, check these two different Google forums that may help solve the problem, ( Google Forum 1 ). ( Google Forum 2 ).
 
Uses of Gmail “Background Send” Lab
Generally when users send an email on Gmail, it’s recommended to wait until the email has been sent before leaving the page. But with the “Background send” lab, it will allow users to exit the page and the email will still be sent.
So a Gmail User can do other works (go to inbox, read messages, clear spam) without wasting the time. This is the main use of “Background Send” Lab in Gmail. But it also create Some Gmail Error 502 in rare cases.