For the past 15 years I’ve been using multiple email addresses to try and separate up my email automatically. I have a main email account, one for developing, another for purchases, and another for mailing lists and so on.
Originally this was to try and keep the email addresses that would be low-priority out of my main inbox. It also helped to keep the spam low by ensuring that I had email addresses that were never publicized anywhere, keeping their content relatively clean.