When you open your account, there's some icon like this..
their functions :
Inbox = place to check your inbox
Starred = where you can find your favorite (starred) email
Important = where you can find important emails, usually those that has file attached
Sent mail = where you can find your email that has been sent
Drafts = your saved email/email that hasn't been sent
And when you compose email..
at the bottom, there's only 4 icon, but, if you click this butto..
These icon will be added..
Send = to send
A = to edit the formatting
to attach files
insert files using drive
insert photos
Insert link
insert emoticons
