diff --git a/src/lib-smtp/smtp-client-connection.c b/src/lib-smtp/smtp-client-connection.c
index 9acc4ff34d..35c4cf662a 100644
--- a/src/lib-smtp/smtp-client-connection.c
+++ b/src/lib-smtp/smtp-client-connection.c
@@ -2030,6 +2030,13 @@ void smtp_client_connection_close(struct smtp_client_connection **_conn)
 	smtp_client_connection_unref(&conn);
 }
 
+void smtp_client_connection_update_proxy_data(
+	struct smtp_client_connection *conn,
+	const struct smtp_proxy_data *proxy_data)
+{
+	smtp_proxy_data_merge(conn->pool, &conn->set.proxy_data, proxy_data);
+}
+
 void smtp_client_connection_switch_ioloop(struct smtp_client_connection *conn)
 {
 	struct smtp_client_transaction *trans;
diff --git a/src/lib-smtp/smtp-client-connection.h b/src/lib-smtp/smtp-client-connection.h
index 3e94f80d4e..fbc716a877 100644
--- a/src/lib-smtp/smtp-client-connection.h
+++ b/src/lib-smtp/smtp-client-connection.h
@@ -58,6 +58,10 @@ void smtp_client_connection_ref(struct smtp_client_connection *conn);
 void smtp_client_connection_unref(struct smtp_client_connection **_conn);
 void smtp_client_connection_close(struct smtp_client_connection **_conn);
 
+void smtp_client_connection_update_proxy_data(
+	struct smtp_client_connection *conn,
+	const struct smtp_proxy_data *proxy_data);
+
 void smtp_client_connection_cork(struct smtp_client_connection *conn);
 void smtp_client_connection_uncork(struct smtp_client_connection *conn);