1. He doesn't go to work every Sunday.
2. He doesn't go to work on Sundays.
3. He sometimes go to work on Sunday, and sometimes doesn't go to work on Sunday.
4. He doesn't go to work on any Sunday.
[Does #1 mean #2? Are both the same? Does #1 mean #3 or #4?]
1 and 2 mean the same thing, yes.
3 is not grammatically correct, but could mean the same as 1 if it's fixed.
4 is the opposite of 1 and 2.