For business use (or for any email account you want to be sure to receive messages), you should probably turn off all auto filters, then setup manual filters for messages you are certain you do not want to see. Yes, this seems backwards, but it is the only way to be sure not to miss anything you wanted to see.
There are other tricks of the trade, such as using special email addresses for things like mailing lists or online shopping (some mail services allow you to "add" things before the @ sign, without having to create specific addresses, which can then easily be filtered/tracked). Or for mail you are having trouble getting seen, send using the same provider, if you can (gmail to gmail for example).
And be careful with the account you use for important sending, as it could get lumped as spam via the various auto filters. I just recently got completely fed up with complaints of messages not being received. Of course, I have NO control over receipt.viewing, only sending. So I have changed to a paid mail sending service which provides actual delivery confirmation (not viewed, as that is not reliable since it requires html messages, and a hidden image, which can be disabled by the reader). Just today, someone is telling me we never sent their receipt. We have sent it several times, and have confirmation it was received by their email provider. Unfortunately, they gave us no phone number, and a bad fax number, so we have to rely on USPS to deliver the printed copy of the message and receipt - since the likely problem is the receipt/receipts was/were sent to their spam folder.
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Speaking of USPS, my nearly 30 year old CBU (cluster box) was broken into. (Likely first of the month meth heads looking to sell a sack of stolen mail for a few bucks, my cameras do not cover the CBU, but a neighbor's does...) Only lost one item I have to replace. Of course, most of the neighbors have no idea it is up to us to pay the 1500+ for a modern CBU (no HOA) and most think USPS will fix it. Most of my mail does go to a POB, but for now, USPS is not enabling forwarding the rest, because of the damaged CBU, and is making me go across town to the main PO. I have to go to the PO unit where my box is to see if they can force the forward through. I did discover something I missed, that my POB allows me to enable a "street" address for my POB, meaning I can have all mail and packages shipped to the "street" address, as long as it is "USPS mail" worthy (under 70 lbs, not alcohol, etc.).