I use canary mail. I've been happy with it. It had some security features that first drew me in. But it also has a nice smart select feature that will higlight what it perceives to be junk, as you scroll your inbox. This makes cleanup a breeze.
Thanks for the reccomends! I was reading a comment yesterday that suggested that since Lemmy instances are privately hosted, the more that is uploaded/hosted here, the more the instance owner is ultimately paying. I figured I'd keep the load (not that kinda load) off of the Lemmy instance, and put that cost on someone else.