You want to look at newsyslog and /etc/newsyslog.conf

It rotates files after certain criteria - size, time, etc.
It will keep N generations of each file.

Read up on it a bit and use subjects in your mail messages.

Quoting Hendro Hadiwinoto (hhadiwinoto@yahoo.com):
> Hi all,
> 
> I use  syslog server for logging all my server. Relate
> to syslog, there are some questions which based on
> kiwi syslog feature as below,
> 
> 1. how to archive of the existing logging file in 
> /var/messages every two weeks automatically.
>    
> 2. how to limit messages file in /var/log less than 1
> Mb. When the messages file reach the limit then
> automatically syslog server put the log in to new
> file.
> 
>  
> 3. is it possible to reserve 5 files in /
> var/log/messages (file messages1 to messages5)  which
> use for logging and do overwrite the 
> all the that can be [done/conducted] by automatically
> by server syslog or having to with script. 
> 
> Any comments/heps would be appreciated.