ETH Zurich partners with SoftwareONE for the distribution of Office 365 ProPlus subscriptions (see Microsoft Office 365 for details). It is not possible to get an Office 365 subscription directly from Microsoft with an ETHZ email address. Unfortunately that means that you can not get invited to another organisation’s Yammer or Teams service with your ETH email address. When you try to redeem such an invitation Microsoft detects that your email address is not connected to an existing Microsoft account and starts the self-registration process which is disabled for ETH domains.
There are a few workarounds: You can ask the other organisation’s contact to invite you using your anonymized Office 365 ETH account (again see Microsoft Office 365 for details) or use a Microsoft account created with a different non-ETH email address. In some cases the inviting organisation may also be willing to give you a guest account in their Azure AD after you explain the situation.
Please note that ETH does not yet offer the Yammer and Teams service as part of its Office 365 ProPlus subscriptions for students and staff. This may change in the future and we are also looking into moving away from the anonymized Office 365 accounts so that it will become possible to use an ETH email address for Microsoft’s cloud services. A time frame for the change has not yet been set.