Drop mail sending for MAC addresses
Drop mail sending for MAC addresses

Instead, append a `rate_limited` tag to isolate these log sampes from
other ones in order to treat them properly.

Fix #108

lukasjuhrich/sipa,MarauderXtreme/sipa,fgrsnau/sipa,agdsn/sipa,agdsn/sipa,agdsn/sipa,MarauderXtreme/sipa,agdsn/sipa,MarauderXtreme/sipa,fgrsnau/sipa,lukasjuhrich/sipa,lukasjuhrich/sipa,lukasjuhrich/sipa,fgrsnau/sipa