First, I do not let my phone make noise when I get any (of over 200) emails per day.
Second, once you have shopped more, you will recognize the ones not worth opening until you have 10 minutes to sift through the dross in case there is a hidden gem. I do that at my computer where it is much faster to sift than on my phone.
Third, once you learn when your favorite MSCs tend to post new shops, you will jump in and grab some before any emails go out.
Fourth, once you have made a good rep with your favorite 10, or so, MSCs you will start being offered enough jobs to fill your schedule quite early in the month and can be really picky about what other emails you open.
Based in MD, near DC
Shopping from the Carolinas to New York
Have video cam; will travel
Poor customer service? Don't get mad; get video.