A recipient computer system submits an anonymous electronic message address to a source computing system for use when the source computing system is to send electronic messages to the recipient. When the electronic message server receives an electronic message, it reads the electronic message address and determines that the address corresponds to the recipient, but only if the electronic message originated from the source. If the electronic message were to originate from a different source computing system, the same electronic message address would not be respected for delivery to the recipient. Accordingly, the electronic message address is specific to a source, and thus sharing the electronic message address has little avail. The association between the address and the recipient may be revoked when the recipient no longer desires to receive messages from the source.