This actually has to do with Gmail. Gmail doesn't necessarily care about periods. We verified this using some of our own personal Gmail accounts and received the message regardless of whether or not there is a period in it. In theory, it’s possible that this hasn’t always been true, and maybe these are legacy accounts, but if that is the case that is something with Gmail that we cannot control.

There is an article on Google that goes more in depth about this issue with Gmail, see here.