O365 external sharing

Occasional Contributor

Dear all,


A customer with M365 E3 license with SPO and EXO deployed is looking for a secure solution to  collaborate between internal business units and external customers (work on documents and share ideas in a secure place).   

Sharing Sharepoint online site collections with external accounts should address the business need. As for security I would stick with either of these options: 

- invitations to guest users limited to site owner only (can be reinforced with external domains inclusion/exclusion )

- global admin managed guest users (guest users must be in AAD). More restrictive but requires global admin involvement.


I noticed that when authenticated as external user on a shared SPO site, when trying to search for People or Everything on the site, I get the "You need permission" page, which is fine, but when trying to Request for Access it throws error:

The specified user i:0#.f|membership|<user email address>#ext#@<tenant> could not be found.

Is this expected behavior knowing that this account exists in O365 admin/users ?


Separately are there any O365 apps in the E3 subscription that would benefit external collaboration (Skype, Yammer) ?  And what would be the effort to implement them ?


Thank you for your feedback.

5 Replies
Hi! See the following thread regarding the search function!


Also regarding the collaboration tool, you should definitely look into Microsoft Teams! It’s part of the license and the purpose is what you describe you need!



Thanks Adam. 

I'm not yet that familiar with Teams and given the customer is not using it to this point, it would require a fair amount of training before being used effectively.  It would however be an area to explore with customer to benefit from its integrated communication capabilities (chat, voice, video).

For this specific case I feel that collaboration is going to be more project focused so SPO should do fine.

I'm also not quite sure yet as to how granular security can be set in Teams vs Sharepoint site/apps/files 

For testing purposes I did create a Team site but I can't add a guest account directly from within Teams even after having turned on guest access in O365 Teams Admin center (org wide settings). I was able to add the guest user from the admin center but the user is still not showing as a member in Teams site. Anything I miss ?

How/where did you add the user?
Guests should be enabled both for teams and for groups
Groups: admin portal - services and addins - groups
Teams - teams and Skype admin portal - guests

After enabling this, it can take some time to propagate!
Also if you added a member already through any other service than teams like directly to the office 365 group and not from teams, it can take some time as well to show in teams

Hi Adam,


I've just delivered my presentation related to this business case to Microsoft to land a job as PFE.

WelI...I should have taken your advice and put more focus on Teams.  While I did cover Teams high level and listed some of its benefits (its free, easy to use and setup, includes a set of linked services, allows for real-time, fast paced collaboration internally and externally etc) and that it could complement SPO, I did  mention some drawbacks (training, desktop client, SPO already in use, more advanced security policies in SPO...) which I probably shouldn't have.

I didn't realize how much of a push MS is giving behind Teams to beat Slack in this segment.

It looks like the interviewers (tech delivery leads) were expecting a sales pitch for Teams more than anything else. Still unsure as to how this relates to a PFE role.


I will have an answer next week but I am not too optimistic about the outcome. 








I have my fingers crossed!