Freelancers receive emails about projects that may be of interest to them, based on the skill categories they list on their profile. To change the frequency of your notifications:
Visit your profile page, (found in the top-right corner of your screen, next to your profile photo and username).
Click the white "Edit" button in the top-right corner of the the intro box at the top of the page.
Scroll down to the bottom field, "Frequency of Project Board Emails." Click the field and select from the three options available.