I’ve been through email bankruptcy a number of a times and a few years ago I landed on a method that has addressed the worst of this situation rather handily. Unfortunately, this approach is dependent on the level of integration and rule sophistication your email client is capable of.
I’m using the Apple Mail App on OS X and to ensure that this is applied consistently, I have a copy running on a VM on a home server that’s always running. It connected to all of my various email accounts and consolidates everything into one master account to simplify the account management on other devices. This is also required so that when I check mail on other devices that don’t or can’t run rules, the filtering has already been done.
Like many geeks, I have the usual set of rules for very common types of inbound mail like cron and log reporting that get auto-filed into appropriate folders. In my hey-day with Eudora, I had smart rules that filed everything, with every single mailing list having its own folder. I’ve gotten a little more lax since then now use some general purpose buckets and rely on search rather than having to know in which sub sub sub folder the message might have been filed. This also avoids the confusion of filing systems that cross metadata boundaries and eliminate the decision fatigue of deciding between Joe, project X, client Y and so on.
The key is that at the bottom of the list, there is a final rule that checks each sender’s address against my address book (the Contacts app) and if they are not present, it gets filed into the bulk folder of “Unknown Sender” which I check on less frequently than the main inbox. This allows me to transform my inbox into a whitelist destination where only people or services that I allow get in. The default gets dumped into the secondary box.
So I order to get into my inbox, it needs to be earned and your address added to the address book. This has been transformative in how I cope with mail.
In a way this allows me to separate mail into different tiers to which I can assign different amounts of attention:
VIP: Apple specific tag for important people in my life, visible in a smart folder across all devices
Inbox: stuff for me, highly probably that there’s useful or actionable stuff here
Unknown sender: Not necessarily spam, but the probabilities are leaning that way
Spam: system decided
Autofiled: reference as required, marked as read when auto-filed