1. A computer-implemented method of associating an organizational entity with a network address, the method comprising: sending an e-mail to a user, the e-mail having a destination address with a domain name corresponding to the organizational entity and including a reference to external content; receiving interaction data describing an interaction with the user over a network, the user associated with the organizational entity, the interaction data comprising a request for the external content and a network address associated with the user during the request; retrieving a record associated with the organizational entity from a database; determining, based at least in part on the interaction data, a score indicating a likelihood that the network address is associated with the organizational entity; and responsive to the score exceeding a threshold, storing the network address in the record associated with the organizational entity.