1. A method for sharing referenced content through collaborative business applications, the method comprising: detecting referenced content in an electronic communication, the referenced content referencing content stored in an external repository, the referenced content identifying a registered external repository connector; determining that an Access Control List (“ACL”) for the referenced content lacks an entry for a recipient of the electronic communication; determining an access control threshold for the registered content, the access control threshold comprising a maximum number of ACL entries permitted to define access rights to the referenced content; generating an ACL entry for the recipient in response to the recipient lacking an entry in the ACL for the referenced content if the generated ACL entry does not exceed the access control threshold, the ACL entry controlling access to the referenced content for the recipient, the ACL entry defined based on a security policy associated with the recipient; determining that storing the generated ACL entry for the recipient causes a number of ACL entries for the referenced content to exceed the access control threshold; and dynamically creating an access group in response to generating the ACL entry for the recipient causing a number of ACL entries for the referenced content to exceed the access control threshold, the access group comprising the one or more recipients having access rights for the referenced object and generating an ACL entry for the access group, the ACL entry controlling access to the referenced content for the access group, the ACL entry defined based on the security policy.