How to send email directly on button click without opening Gmail(SMTP)

I want to send mail on a button click without opening Gmail
I am read all over web but not able to get solution.
Can someone please suggest this to me.

Did you search in Community.
Read this post full may help you else search on Community for email

@ShaikhSajidAli from this I do not get solution

Read post from start there are different ways to do it nand search on Community

Still not found