Thanks for such a great plugin.
I have a WP Network with only two sites, the primary and one secondary. Both have the same admin email address.
When I try to set up Peters Collaboration Emails on the secondary, I get this error message:
Warning: Invalid argument supplied for foreach() in / - blog URL - /wp-content/plugins/peters-collaboration-e-mails/peters_collaboration_emails.php on line 949
http://wordpress.org/extend/plugins/peters-collaboration-e-mails/
Still seems to work fine on the primary blog. It was set up there prior to switching to network mode.