This study examined intertextuality and interdiscursivity in email exchanges in an Institute in Malaysia. Intertextuality observed how and why the discourse community repeatedly used certain forms to respond to reoccurring rhetorical situations and how they used their professional knowledge to identify the authority of certain texts on other text. Interdiscursivity examined how and why the employees of the Institute appropriated the generic resources of a genre to create another. This study found that the discourse community skillfully used three types of intertextuality to achieve similar and contradicting communicative purposes. They also appropriated generic resources of a genre to create another.