According to this Q&A https://stackoverflow.com/questions/20919325/should-i-remove-all-dots-before-the-sign-in-emails, 'dot' is a valid character in an email address.
But for Google's gmail service, they say they do not recognise 'dot'. Quoted from https://support.google.com/mail/answer/10313?hl=en
Gmail doesn't recognize dots as characters within usernames, you can add or remove the dots from a Gmail address without changing the actual destination address; they'll all go to your inbox, and only yours.
I am using 'Gmail for Work' at the moment. Let say my work domain is '@awesome.com'. To my surprise, 'j.e.n@awesome.com' caused a bounce from google. I am expecting the email will be delivered to 'jen@awesome.com'
Does 'Gmail for work' handle email address differently?
Best Answer
Gmail for work/Google Apps accounts do count dots as part of the email address so the two address are unique. From this help article: