Manage recipients in standalone EOP

Standalone Exchange Online Protection (EOP) organizations without Exchange Online mailboxes support the following types of recipients:

• Mail users: Mail users are the fundamental type of user accounts in your standalone EOP organization. Mail users have sign in credentials in your EOP organization, but they have external email addresses (their mailboxes are located outside of your EOP organization).

  For more information about managing mail users, see Manage mail users in Exchange Online (and EOP).

• Mail contacts: Contacts have external email addresses, but no sign in credentials in your EOP organization. the mail contact is visible in your organization's shared address book (also known as the global address list or GAL) and other address lists.

  For more information about managing mail contacts, see Manage mail contacts in Exchange Online (and EOP).

• Groups: You can create the following types of groups:

  • Microsoft 365 Groups: For more information, see Create a group in the Microsoft 365 admin center.
  • Distribution groups: For more information, see Create and manage distribution lists in Exchange Online (and EOP).
  • Mail-enabled security groups: For more information, see Manage mail-enabled security groups in Exchange Online (and EOP).
  • Dynamic distribution groups: For more information, see Create and manage dynamic distribution groups in Exchange Online (and EOP).