diff --git a/include/mail.hpp b/include/mail.hpp
index 5cfd067..2503184 100644
--- a/include/mail.hpp
+++ b/include/mail.hpp
@@ -14,7 +14,12 @@ namespace mail {
         std::vector<std::string> body;
     };
 
-    using session_map_t = std::unordered_map<protocol::session_t, message_t>;
+    struct session_t {
+        bool has_header = 0;
+        message_t message;
+    };
+
+    using session_map_t = std::unordered_map<protocol::session_key_t, session_t>;
 }
 
 #endif
\ No newline at end of file