I found an email from my gmail inbox which claim to be sent by me, but in fact i did not send it. Does it mean someone has hacked into my mail box?
Posted on 2011-10-31
Why am I seeing the error "This message may not have been sent by...."?
Why am I seeing this warning?
You'll see this warning if a sender is claiming to be from Gmail, but we couldn't confirm that the email originated from a Gmail sender. For example, you might receive an email claiming to be from email@example.com that was not actually sent from Gmail. All mail sent by Gmail should have specific information in the message (called authentication data) that can verify that the message was sent by Gmail. If you see a warning message indicating that a message may not have been sent by a Gmail user, this means that the authentication data is missing. The information that we use to detect the sender is included in the message headers, but these headers can be hard to understand. So, Gmail analyzes this information and displays it in a simple to read format, for your protection.
The missing data can be an indication that the message was forged and not really sent by the sender, or that it was sent by the sender through a website or a sender that did not provide information about the origin of the message (for example, a website sharing a news article with you). If the email wasn't sent by Gmail, but the sender authenticated the message and provided information about who sent the message, we'll show you the sender's name and the service that authenticated the message. For example, if firstname.lastname@example.org sent you a card from a website called ecard.com, you'd see the sender listed as "email@example.com via ecard.com."