Strange GMAIL Functionality, but its a BUG

For some days I have been receiving mails sent to other address the difference between that address and mine is a single dot. When I researched further, I found that its a functionality, how GMAIL works. Read from here.

According to google, Gmail doesn’t recognize dots (.) as characters within a username. This way, you can add and remove dots to your username for desired address variations. Messages sent to your.username@gmail.com and y.o.u.r.u.s.e.r.n.a.m.e@gmail.com are delivered to the same inbox, since the characters in the username are the same. But you have to use dot in order to log into your account.

They shouldn’t allow dots at first place, if this was the case. If you have an email address that has dot in it then change it ASAP. You might be loosing confidential data to someone else.

Does this mean Google mail is not secure?