FindEmailAt

NTSTATUS __stdcall FindEmailAt(PWCHAR pInput, INT64 cchInput){
  int v2; 
  WCHAR *v3; 
  v2 = cchInput - 1;
  v3 = &pInput[(int)cchInput - 1];
  if( (int)cchInput <= 0 )
    return cchInput;
  while( *v3 != 64 )
  {
    --v3;
    if( --v2 < 0 )
      return cchInput;
  }
  return v2 + 1;
}

Referenced by:

RtlpNameprepAsciiRealWorker
RtlpValidateAsciiStd3AndLength