In emails I address them as " Professor [so and so]" when talking I call them by their first name, cuz most professors are cool and like being on first name basis with their students. as for "madam" hahaha...dont use that word man, use "ma'am" instead, works much better. like "yes ma'am" it will still turn a few heads, but not as much if u said 'yes madan'. Never use " yes my mistress". ull get sued:).. I dont think its a big deal to address (when emailing) them with "prof." . I personally never use "doc" to address them. "Dr." works much better for me.