Is it possible to show different address in sender address than the actual

Hi All

Today a very strange thing happened with me. I received an email from my own Gmail account to my other hotmail account. The email was visibly a phishing email (lottery with link shortners). The surprising thing is that I never sent the email and I am pretty sure that my account was not hacked. I checked the detailed login history also. Plus there is no security alert. Other major thing is that there is no such sent email from my Gmail account. But when I replied to this email from my hotmail account, the email arrived to my gmail account only. I don't understand how this is possible. Is there any possibility of showing email other than the actual sending email? If yes, then how come the reply landed in my gmail account.

I wonder if anyone of you have experienced it and how to make sure my gmail is not hacked.