I had an idea for controlling spam that works really really well for me. I modified my email forwarding to look like this:
email@example.com -> ABC@gmail.com -> XYZ@gmail.com
XYZ@gmail.com is the only account that I actually read on a regular basis.
I just had a case where a spam message to firstname.lastname@example.org which can be viewed in my Inbox on ABC@gmail.com. In other words, it wasn't auto filtered to ABC's Spam folder. Well, that message never got forwarded to XYZ@gmail.com. I can't explain why and so far, all of the valid email has gotten forwarded.
So, my Spam folder on XYZ@gmail.com stays clean except for spam that was sent directly to XYZ@gmail.com. Thus, there is barely anything that I need to skim over when purging my Spam folder on XYZ. Very handy.
email@example.com has been around since 1996. It gets a lot of spam.