"Hi Neil,

I am the email manager at Wetpaint. Sorry your class is not receiving their invitations! I know we aren't having any email delivery problems at Gmail right know, but you mentioned your school uses a customized version of Gmail. Perhaps there are different security settings on that system that prevent your class from receiving email from Wetpaint.

There are a few options.

1. You could send invitations to alternate email addresses for your students (outside of the University's security filters).

2. You could make your site public (not private) for a small window of time, allowing your students time to visit the site and join w/out receiving an invitation. After everyone has joined you could turn the site back to private.

3. You could contact your systems administration and ask them to allow or "whitelist" email coming from the domains wetpaint.com and wetpaintmail.com. They might also need an IP address, which is 72.32.211.141.

"