Hello @Vernita_Kruger,
so sorry to hear about the issue you are facing. Another experienced the same problem and shared here on how he was able to resolve it: Recent email security update. How to fix “We couldn’t process your email” - #38 by Christian_Quiros
If that does not help and as you mentioned you are still using the same email under which your domain is registered also then I recommend reaching out to Asana support to look into this.