public Response sendReceive(final String msg) throws IOException {
        this.send(msg);
        return this.receive();
    }
Sends a message to the server, ie "HELO foo.example.com". A newline will be
appended to the message.

@param msg should not have any newlines
@return the response from the server
src/test/java/de/gessnerfl/fakesmtp/smtp/client/SMTPClient.java