As discussed in my previous blog post Top 3 Reasons Why SharePoint Online Rocks
, depending on your plan, you can enable access to either 500 or 10,000 external users. As a collaboration tool with customers, partners, etc. this is an invaluable tool. While allowing external users to view your on-premise SharePoint portal is certainly possible, it isn't quite as simple of a process, especially if you are within a government organization with strict firewalls. Below I walk you through the process of enabling sharing of your portal with external users and the process through which a user with a Gmail account would access your site.
1. From the Office 365 Administration site, click on Manage within the SharePoint section.
2. Within the administration center, click on Manage site collection.
3. In the Site Collections ribbon click Settings, then Manage External Users.
4. Click Allow, then click OK.
5. Access your team site and click Site Actions, then click Site Settings.
6. Within the Site Collection Administration category, click Site collection features.
7. Click on Activate for the External user invitations feature.
8. When activated, the Active button will be displayed.
9. To share your site with an external user, click Site Actions, Share site.
10. Decide whether the user will be a part of the Visitors (Read access) or Members (Contribute access) group and enter their email address in the provided box, then click on the verify icon to ensure it is a valid email address.
11. The verified email address will be underlined. Enter any text in the Message box to personalize the email to your external user, then click Share.
12. The user will receive an email and they will click Accept your invitation!
13. They will be given 3 choices, to login with a Windows Live Hotmail account, Microsoft Online Services ID, or Sign up for a free Hotmail login. I will demonstrate signing up for an account. Click Sign up.
14. Click the grey Sign up button in the bottom left.
15. Fill out all pertinent information for your new Microsoft account and click I Accept.
16. You will be redirected to your new Windows Live email inbox.
17. Go back to the URL in step 13 from your original invitation email. And click the Windows Live Hotmail login button on the left.
18. Sign in with your new Hotmail credentials.
19. You will be redirected to the collaboration site. You can now login directly to the site from the screen in step 18.