Most people who “try filters” build one rule, watch it fail, and go back to deleting mail by hand. The idea was never the problem. The rule was written against a subject line the sender rewrites every Tuesday, or it was told to delete instead of archive, or its author ticked one checkbox and watched four years of receipts vanish in a single click.
Filter on the envelope, never the marketing copy
Subject lines exist to get opened. Addresses exist to be routed. Build every rule from a sender domain, a list ID or the presence of an attachment, and the rule keeps working when the newsletter rebrands itself for the third time this year.
Gmail accepts real operators in the search box, and whatever you type there becomes the filter’s match condition:
from:(@mail.figma.com)covers every variant under that subdomain, including the billing and noreply addresses.list:(<announce.example.com>)matches the List-ID header that proper mailing-list software writes, which survives a display-name change.has:attachment filename:(pdf|docx)separates invoices and contracts from conversation.larger:10M older_than:1yfinds the dead weight worth clearing out.to:([email protected])works if you plus-address at signup, and quietly splits retail from everything else.
The Gmail filter that keeps working after a rebrand
Open the gear icon, choose See all settings, then the Filters and Blocked Addresses tab, and click Create a new filter. Paste the operator, hit Create filter rather than the magnifier, and you get the real action list.
Tick Skip the Inbox (Archive it), apply a label called Newsletters, and add Never send it to Spam for any legitimate sender that publishes too often. Leave Also apply filter to matching conversations switched off until you have watched one new message match correctly. That checkbox is the dangerous one: combined with “Delete it” it removes years of mail instantly, and Trash only buys you thirty days.
Two structural details matter. Gmail stops accepting filters at 1,000 per account, and rules are evaluated in the order you created them, so a broad “archive everything from @github.com” rule makes every later, more precise rule pointless. Write narrow rules first, broad rules last, and name labels with a numeric prefix such as 2-Newsletters so the important ones sort to the top of the sidebar.
Outlook rules need a stop switch
On the web: gear icon, Mail, Rules, Add new rule. Set the condition to “From” containing the domain, choose “Move to” a folder, and switch on Stop processing more rules for anything broad. Without that toggle, a catch-all rule and a specific rule both fire and you end up with mail in two places.
In desktop Outlook, Home > Rules > Manage Rules & Alerts > New Rule > Apply rule on messages I receive. Priority is literal: the arrows in that dialog move a rule up or down the list, and the first match with a stop switch wins. Outlook stores rules in a 64 KB block per mailbox with a 32 KB ceiling per rule, so a rule carrying forty exceptions eventually refuses to save — that is the usual explanation for a rule that simply disappeared.
Rules also only run at delivery. To sort what already landed, use Run Rules Now and pick the folder explicitly, or you will scan the whole mailbox for an hour.
Apple Mail and the “only when open” trap
In Mail, go to Settings > Rules. Those rules run only while Mail is running, so a Mac that sleeps from Friday to Monday leaves the weekend unsorted. For mail that must be routed regardless, use iCloud Mail rules at icloud.com > Mail > gear > Rules; they execute on Apple’s servers but can only file messages into iCloud folders, not local ones. Apple’s guide to sorting incoming mail automatically spells out that limitation.
Four rules that backfire, and how to test one safely
Never write a rule that deletes anything from a bank, an airline or a two-factor provider. Fraud alerts and boarding passes are exactly the mail a filter cannot be trusted with; instead send them the other way, with from:(@yourbank.com) set to Never send to Spam and a label. Don’t filter on the word “unsubscribe” in the body, which matches every newsletter and nothing else. Don’t auto-forward to another address, since many providers drop forwarded mail silently. And don’t match on to:[email protected] if you use aliases or BCC, because both bypass it.
Test each new rule before trusting it. Send yourself a message with subject TESTFILTER from the target address, confirm it lands in the right label, then delete the test. When the system settles, export a copy: Google Takeout includes a filters file under Mail if you tick that box, which is the only sane backup for a few hundred rules. Google’s own walkthrough is at Create rules to filter your emails, and Outlook’s is Manage email messages by using rules. If the inbox still feels out of control afterwards, the triage routine in the fifteen-minute inbox system handles what filters cannot, and spotting a phishing email in ten seconds covers the messages that should never have reached a label at all.