Fixed a Buffer building bug: to make sure the value passing into Buffer constructor is a real string rather than an integer and avoid making a `new Buffer(int)` by accident from user's wrong input type
Fixed a Buffer building bug:
to make sure the value passing into Buffer constructor is a real string rather than an integer and avoid making a `new Buffer(int)` by accident from user's wrong input type

andris9/simplesmtp,frontapp/simplesmtp