USING VIRTUAL NETWORK ADDRESS INFORMATION DURING COMMUNICATIONS

Techniques are described for employing virtual network address information in communications with other computing devices or software programs. In some circumstances, the techniques are used by a computing device that hosts multiple virtual domains each having a distinct domain name and having one or more virtual users of the domain. If so, the host computing device communicates with others on behalf of the virtual domains or virtual users by employing virtual network address information as part of the communications.