Hello and sorry you're having a problem with Puzzlements.co. If you're accessing the site from a school network or using a school email address, you'll need to contact your district's IT folks. They're almost certainly doing something funky.
Otherwise, here is my best advice if you're not receiving the emails:
Sign up using a personal email account (gmail/yahoo/etc), not a school/district email account.
Check your spam or junk folders.
If you signed up with a district email, contact your IT people for support. They are probably filtering email in some way.
Whitelisting or adding firstname.lastname@example.org to your contact list may also help the emails to get through.