Maille is pretty heavy (20 pounds). Might not sound like a lot but getting maille on is no easy feat.
Depends what weave and metal you have. Aluminum wouldn't be bad, but even the lightest 4-in-1 steel maille can weigh in at close to 30 pounds. Also, I once went onto my street with a trench coat on and a towel on my head (don't ask) and I received some um.. not so nice gestures from a couple of people in cars.