Another approach is to grep thru the last 10 days of maillog.*.gz and see if this ip has every contacted your MTA before.
If not, then blocking that ip isn't going to bother your clients.
Another approach is to grep thru the last 10 days of maillog.*.gz and see if this ip has every contacted your MTA before.
If not, then blocking that ip isn't going to bother your clients.