Microsoft has been touting a functionality for Microsoft Teams since June that would allow users outside your company to collaborate internally with your group. Unfortunately, that Guest Access ability has faced a rough road, again being delayed until sometime next year.
Guest Access was supposed to roll out at the end of June, but Microsoft officials backed off on that date, pushing it back to September. The company did start rolling out a version of Guest Access then, but it was only for people with an Azure Active Directory account. Company officials said that allowing access to anyone with a Microsoft account (MSA) was still a few weeks away.
With November coming to a close, there is still no sign of the functionality. Program Manager Suphatra Rufo finally tweeted that the new release date should be in a few months. ZDNet asked Microsoft for a confirmation of the 2018 timeframe, but a spokesperson only said that "Microsoft is working on guest access for MSA, but doesn't have details to share on timing."
Hiya #MicrosoftTeams folks. I owe you some updates. Guest Access MSA should be here in a few months. Private channels is well under way. We'll be releasing a bunch of little + fun features i.e. hide chat, likes in chat, this coming month. I'll be updating UserVoice furiously!— Suphatra Rufo (@skprufo) November 29, 2017
"Trust me, this is our top priority! It is just a very difficult feature for us to implement as it requires work from multiple engineering groups across the company. We are working hard at it and really appreciate your patience!"