Sometimes we receive multiple emails for a single event even though we have configured to send notification only once.
Open the stdlog file as per the time stamp and see whether you get messages similar to below:
09/04 16:22:49.89 g1dwsdap spelsrvr 4084 ERROR alg.spl
701 Error setting log analyst 793ED69B4E87A545BD8E911834D829FC: NOT FOUND
09/04 16:22:49.90 g1dwsdap spelsrvr 4084 ERROR 13 macro event error 'AHD05026: Error creating Activity Log Entry.
09/04 16:22:50.06 g1dwsdap animator_nxd 2632 ERROR animator_nxd.c 1726 AHD03075: Required attribute is missing. (attribute: type object: alg) in animator ANI:400151 (cr:401040) for atev:400716 in method animation_complete
If yes then please check the UUID of the contact System_AHD_Generated whether it is ?793ED69B4E87A545BD8E911834D829FC?.
If it is different then please follow the below steps in restoring its correct value: