- user registration
- registration certificate request
- purchase of a work for sale
- ... ... ... ?
First check your inbox spam (junk mail).
If our verification or to download email is nowhere to be found it's likely that your email server is mismanaging "received" emails and making false unwanted email positive assumptions, removing at its discretion mails that completely fails to deliver.
Using @hotmail.com for these tasks can be problematic for this very same reason.
How may I solve it?
You can go to your hotmail settings of your account (top right gear icon), to "More email settings", "Safe and blocked senders", "Safe senders", write "firstname.lastname@example.org" address and "Add to list".