Milter-greylist

In the source, I see:

        #define GLDELAY       1800    /* 1800 seconds = 30 minutes */

In my config file, there is only one delay statement:

        racl greylist list "grey users" delay 30m autowhite 3d

In emails, I see:

        X-Greylist: Delayed for 00:26:40 by milter-greylist-4.2.3
        X-Greylist: Delayed for 00:21:04 by milter-greylist-4.2.3
        etc.

Why?