String regEx = 
  "^(([\\w-]+\\.)+[\\w-]+|([a-zA-Z]{1}|[\\w-]{2,}))@" 
    +"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?" 
    +"[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\." 
    +"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?" 
    +"[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|" 
    +"([a-zA-Z]+[\\w-]+\\.)+[a-zA-Z]{2,4})$"; 
 
  public void btnValidateEmailAddress(View v) 
  { 
  strEmailAddress = editTextEmail.getText().toString().trim(); 
 
    Matcher matcherObj = Pattern.compile(regEx).matcher(strEmailAddress); 
 
    if (matcherObj.matches()) 
    { 
    Toast.makeText(v.getContext(), strEmailAddress+" is valid", Toast.LENGTH_SHORT).show(); 
    } 
    else 
    { 
    Toast.makeText(v.getContext(), strEmailAddress+" is InValid", Toast.LENGTH_SHORT).show(); 
    } 
  }