Two things… how are you seeing anything on the serial monitor?? your primary Serial link can only do one thing at a time, load the sketch, then after running the USB-link, connect the device to the internet via the Serial link. Any attempt to tap into that COM port (from the PC side) or use BLYNK_PRINT Serial or any other Serial print will interfere with that connection. Eventually you can use softserial and a USB-TTL adapter , but that is another issue for another day 
And as far as the email… start small and set up a single email that happens right after Blynk.begin(Serial, auth); but is not called in a loop. Once that works then you can work toward a control method that will send additional emails on command without flooding.
Also, you must have the email widget in your App project… nothing to set up in it, but it needs to be there.