Dots don't matter in Gmail addresses. You may want to consider requesting an alternative email address from your user. 

If someone accidentally adds dots to your address when emailing you, you'll still get that email. For example, if your email is johnsmith@gmail.com, you own all dotted versions of your address:

  • john.smith@gmail.com
  • jo.hn.sm.ith@gmail.com
  • j.o.h.n.s.m.i.t.h@gmail.com

This Google Help document has additional information. 
  • Note: We provide links to third-party websites in an effort to help you resolve your issue. We are not responsible for the information on third-party websites and we cannot assist with implementing resolutions from these websites.