One of the first things I recommend users do after installing WordPress is to either close user registration or install a plugin that protects the site against spam registrations. A friend of mine recently started a new WordPress site that has BuddyPress installed.
After two weeks, I chipped in to help him out and discovered more than 300 registered spam accounts. To make matters worse, these accounts were able to create new groups in BuddyPress and each one contained spam content. The first thing I did was close user registration then I began the boring process of removing the accounts.
We ran into an issue where legitimate users needed to create accounts while user registration was closed. After asking for suggestions on Twitter and performing a few Google searches, I discovered the Invite Anyone plugin by Boone Gorges. Invite Anyone allows registered members to invite people to register to the site via email while registration is closed.
Using variables provided by the plugin, you can customize the email invitation subject line, the invitation message, and the text at the end of the email. I used the default values which happened to suit my needs. You can also give registered users the ability to customize the invitation subject line or message body and limit the number of emails members can send at one time. In my case, the most important setting to enable was allowing email invitations to be accepted even when site registration is disabled.
There are other configuration settings as well such as controlling who can send emails and limiting group invitations. Invite Only also has built-in support for CloudSponge, a service where users can invite anyone from their address books without leaving your site. Stats are built-in as well but during testing I couldn’t get the Stats tab to load. The Stats tab loads the General Settings page instead.
Here’s what Invite Anyone looks like from a user’s BuddyPress profile page. In addition to inviting someone to the site, users can also invite them to a BuddyPress group as well.
I’m using this plugin on a site running WordPress 4.7 and it’s functioning as expected. So far, we’ve invited three people and all of them were able to successfully register an account despite user registration being disabled. If you use BuddyPress and need a free solution that implements a user invitation system, I recommend Invite Anyone.