English is a language where no one can be perfect.
English is an alien language for Indians. So it's only natural we make mistakes. I would be rather surprised if no mistakes are made!!
Regarding spelling mistakes, well I am not a regular typist. I use single finger typing and I am bound to make mistakes but may not be too awful mistakes which change the meaning.
If any one doesn't follow other's good english, the options are to ask for clarification, with the hope that would be understood or better still, ignore the lack of understanding.
If there is a mistaken understanding, repeat the point and explain what you understood by it andif roght, the response. The Japanese always do it by repeating whatever is told by some one else for confirmation.
Looking forward to more views of the group.