Hi Leong YC,
I think you can build a custom Report using OCUM or with OC Report and you can also schedule the snapmirror alerts.
or else
Go through the script in the given link which explains you retrieve the snapmirror status info through powershell script.
http://www.jasemccarty.com/blog/?p=554
and this thread too
https://communities.netapp.com/message/116665 which gives you the idea about script and the output through mail.
Hope you may find it useful.
Regards,
Hari.