I would like to invite a set of email addresses to my Google+ community. How do I accomplish this using the web interface?
From the Google+ Help:
Invite people to your community
You can invite circles, individual Google+ users, or email addresses to join your community -- up to 500 people at a time. Having more people usually increases the number of posts in your community, and encourages others to use it.
Important (for moderators/owners): If you invite an email address that person will get an email inviting them to join the community (unless they've opted out of getting such emails). The email will include a link to join the community that can be used once by anyone, not just the person you invited. For example, if the person you invited forwards their community invitation email to another person before clicking the link in the email, the person they forwarded the message to could use the email link to join the community. Also, if you invite an email address to the community, other moderators and owners will be able to see it.
Tip: Anyone can share a community by clicking the "Share this community" button. When you click it, you’ll create a Google+ post that links to the community’s page. But it won’t create an actual invitation for people to accept or decline.
Invite people to join your community
- Open Google+.
- In the upper left corner, click the drop-down menu v > click Communities.
- Click on your community.
- In the top right corner, click Invite people in the “Spread the word” box.
- In the “Add a comment” box, you can explain a bit more about your community or why you’d like people to join.
- In the "To" box, add who you’d like to invite. You can invite your circles, individual Google+ users, or email addresses.
- In the lower left corner, click Send.
How to invite people to join your community from Android app and iPhone/iPad app see the help page.
You can’t invite someone to a community on a mobile browser. Please use a computer or the Google+ app instead.
Cancel an invitation to join your community
If you're the owner or moderator of a community and you change your mind about someone you’ve invited or that’s been invited by another member of the community, you can take back their invitation.
Important: If someone invites an email address that isn't associated with a Google+ account to a community that anyone can join, you won't see their invitation or be able to cancel it.
Tip: If you need to remove someone who's already joined your community, you can follow the instructions included in the "Remove members" section of this article.