meh = rude

When your friend call you at msn,

how will you answer them?
hello? hi? hie? morning? how do you do? and.. ?
Hornestly, 'what' or 'wassup' is my answer.
In cantonese, I used to answer 'meh'? 'meh' = what
People may said I'm super duper unfriendly!
And they will ignoring me.
I thought chatting with close friends,

we can avoid the courtesy words.
Guess I'm wrong.