Hi Sara,
So, looking at various recent account registrations, I'm now noticing that certain email providers have consistently been having problems getting our activation emails, for roughly the past 4-5 months. I'll investigate the root cause and follow up here for everyone's benefit.
For your case specifically - would you like to use the same username as your previous registration attempt? If so, I can delete the previous registration so that you can re-register with the same username but different email address. To confirm, let me know what the username is (either here or in a private email).