An exemplary embodiment of the invention relates to a method, system, and storage medium for providing interoperability of email and instant messaging services. The method includes receiving a request by an email recipient to respond to an email message using an instant message application, retrieving an instant message address for the email sender from storage, and associating the instant message address of the email sender with an instant message composed by the email recipient. The retrieval of the instant message address for the email sender is accomplished by mapping the email sender's address with a corresponding instant message address for the email sender. The method further includes transmitting the instant message to the instant message address using the message application. Other embodiments include a system and a storage medium.