How to sort email addresses?

If a person can use different Gmail addresses to create his/her Spotify accounts by just altering his/her email addresses by inserting a period in the address, doesn't this spell some sort of mistake in their development?

• Answer:

  No, it was done on purpose.  They ignore dot characters in addresses because they don't want the only differentiation between two different accounts to be the presence or the absence of a dot. By the time GMail was developed, both and were very common conventions for email addresses. If both were allowed, and with them referencing separate accounts, there would be too much likelihood of JohnDoe and John.Doe getting each other's mail, which would make for two unhappy users, or worse: one unhappy user and one happy impostor.  They also allow appending a plus sign followed by arbitrary extensions