I have had trouble with my daily/weekly periodic reports never making it to my GMail account.  Sascha Wildner pointed out to me that periodic.conf has its own answer already:

daily_output=”/var/log/daily.log”
daily_status_security_output=”/var/log/security.log”
weekly_output=”/var/log/weekly.log”
monthly_output=”/var/log/monthly.log”

… and newsyslog is already set to take care of them.  There’s more in the periodic.conf man page.