For both standard customers, and Sponsored Access users, by default, counterparty groups are not visible to new companies joining Symphony Messaging.
Counterparties need to explicitly enable discoverability for all companies or for specific companies they would like to engage with over Symphony Messaging.
Counterparties receive an alert each time a new organization joins the Symphony Enhanced Directory. They can then decide to engage and make their groups visible to that new organization.
If you need help establishing a connection with an organization, contact Symphony via a known representative or by sending an email to sales@symphony.com.