Want an Event report in 15 minute time frames

Hello I want to generate an email report on our syslog once every 15minutes listed down with the events on that time frame. Not a mail for every syslog. Sort of a Rollup email that includes whatever was seen in the last 15 minutes. EG: if 1 Syslog in last 15 minutes 1 Email with those. 10 syslogs in last 15 minutes 1 Email with those. 20 syslogs in last 15 minutes 1 email with those thank you, any help much appreciated.