The elements of the B2B collaboration invitation email

Invitation emails are a critical component to bring partners on board as Microsoft Entra B2B collaboration users. It’s not required that you send an email to invite someone using B2B collaboration, but it gives the user all the information they need to decide if they accept your invite or not. It also gives them a link they can always refer to in the future when they need to return to your resources.

Screenshot showing the B2B invitation email

Explaining the email

Let's look at a few elements of the email so you know how best to use their capabilities. These elements might look slightly different in some email clients.


The subject of the email follows this pattern:

<username> invited you to access applications within their organization.

From address

We use a LinkedIn-like pattern for the From address. This pattern should make it clear that although the email comes from, the invitation is from another organization. The format is: Microsoft Invitations or Microsoft invitations on behalf of <tenantname>


For the Azure service operated by 21Vianet in China, the sender address is
For Microsoft Entra ID for government, the sender address is

Reply To

The reply-to email is set to the inviter's email when available, so that replying to the email sends an email back to the inviter.

Phishing warning

The email starts with a brief warning to the user about phishing, alerting them that they should only accept invitations they're expecting. It’s good practice to make sure the partners you’re inviting won't be surprised by your invitation by mentioning it to them ahead of time.

Image of the phishing warning in the email

Inviter's information and invitation message

The email includes the name and primary domain associated with the organization sending the invitation. This information should help the invitee make an informed decision about accepting the invitation. The inviter can include a message as part of their invitation to the directory, group, or app, or when they use the invitation API. The message is highlighted in the main section of the email. The inviter’s name and profile image are also included if they’ve set one. The message itself is a text area, so for security reasons, it doesn't process HTML tags.

Image of the invitation message in the email

The next section of the email contains information about where the invitee will be taken after they accept the invitation, and a button or link to do so. In the future, the invitee can always use this link to return to your resources directly.

Image of the accept button and redirect URL in the email

The footer contains more information about the invitation being sent. There's always an option for the invitee to block future invitations. If the organization has set a privacy statement, the link to the statement is displayed here. Otherwise, a note indicates the organization hasn't set a privacy statement.

Image of the footer section in the email

Blocking an organization (unsubscribing)

In the invitation from an organization, the footer contains an option to Block future invitations. A guest user can select this link to block any future invitations from the organization. This action also adds the organization to the user's unsubscribed list at

Viewing organizations you've blocked

A guest user can follow these steps to view or export the organizations they've blocked:

  1. Go to
  2. Enter your email and follow the sign-in steps for email one-time passcode authentication.
  3. View the organizations you've blocked, or export the names using copy and paste.


    If you want to allow an organization you’ve blocked to invite you again, you can choose the organization and select Next.

How the language is determined

The language presented to the guest user in the invitation email is determined by the following settings. These settings are listed in order of precedence. If a setting isn’t configured, the next setting in the list determines the language.

  • The messageLanguage property of the invitedUserMessageInfo object if the Create invitation API is used
  • The preferredLanguage property specified in the guest's user object
  • The Notification language set in the properties of the guest user’s home tenant (for Microsoft Entra tenants only)
  • The Notification language set in the properties of the resource tenant

If none of these settings are configured, the language defaults to English (US).

Next steps