As long as you have everything locked down (not updating one part of Blynk but not all others) then once functional, it should stay functional.
@DaleSchultz This aspect of Blynk is the development stage, so prone to many changes over time. I am sure the production/commercial aspect will be long term stable as needed. EDIT - I see Pavel already answered 
Not personally… but I am sure you can Google for various methods.
As far as your current Blynk setup. This sounds similar to a few other widgets (Timer and Timer Input) not quite getting their user setting changes recognised by the server.
Since everything is stored on the server and not your phone, you can also try removing the email widget, then removing the App, then reinstalling the App, but this time use the latest Beta App, followed by the email widget.