Is it better to use labels or folders to filter email?

Labels and folders do the same job when filtering email: grouping a sender's messages together. Gmail uses labels, and a message can have several; Outlook uses folders, and each message sits in just one. What matters is that the filter always leaves the email somewhere you can look for it later.

Can I create a Gmail filter from an email I already have?

Gmail lets you create a filter from an open email: the three-dot menu includes the option to filter similar messages, which fills in the sender automatically. It's worth checking the criterion before saving and applying it to existing messages to see which emails it catches.

Why doesn't an Outlook rule work on my phone?

An Outlook rule that doesn't work on your phone is usually a client-only rule: it's stored in desktop Outlook and runs only when that program is open. Rules created in Outlook on the web are applied on the server and affect all devices.

Is it a good idea to automatically delete email I don't want to receive?

Automatically deleting email with a filter is almost never worth it, because the mistake goes unnoticed: if the criterion catches a legitimate message, it ends up in the bin without warning. For newsletters it's better to unsubscribe, and for unwanted email, mark it as spam so the provider can detect it.

Published on 28 October 20265 min readMadrugo team

Gmail and Outlook filters: a table of useful and useless rules

The short answer: the filters worth having are those that act on stable, predictable senders, such as invoices, tool notifications or newsletters, and that label or archive without deleting. The ones that don't pay off are those that rely on individual words in the subject line, those that delete or mark as read emails from people, and those that forward to other accounts unchecked.

A three-question test before creating a filter in Gmail or Outlook

A filter only deserves to exist if it gets a yes to three questions, in this order:

Is the sender always the same?: the rule has to rest on a fixed address or domain. If the criterion is a word in the subject line, sooner or later it will catch what it shouldn't or let through what it should catch.
Would you always do the same thing with that email?: if the answer never changes (save the invoice, read the newsletter at the weekend), automate it. If it depends on what the message says, decide for yourself.
Can you undo a mistake?: labelling, moving to a folder or archiving can be reversed in seconds. Deleting or forwarding to another account can't always be undone.

If even one of the three fails, the email stays in the inbox and is handled manually. A dubious filter costs more in lost searches than it saves in clicks.

Email rules that are worth it and rules that aren't, in a table

Useful rules share two traits: the criterion is stable and the action is reversible. This table applies the test above to the most common rules:

Rule	Criterion	Action	Worth it?
Invoices and receipts	Supplier's address	‘Invoices’ label and archive	Yes
Alerts from work tools	Fixed sending address	Label and skip the inbox	Yes, if you check them in the tool itself
Newsletters	Sender's domain	Reading folder	Yes
Boss or key clients	Specific sender	Star or colour category	Yes, but never archive
Subject containing ‘urgent’	Word in the subject line	Mark as important	No: anyone can write it
Emails you're copied on	Being in the CC field	Mark as read	No: genuine alerts get lost
Annoying sender	Address	Delete	No: better to unsubscribe
Forwarding to another account	All email	Forward	No, except in specific, reviewed cases

The rule for emails you're copied on is the most tempting and the riskiest: plenty of people copy in whoever needs to know about something. To sort newsletters and notifications in more detail, see the guide on separating newsletters and alerts.

4 mistakes when setting up automatic filters in Gmail and Outlook

The costliest mistake is a filter that archives without labelling: the email leaves the inbox and there's nowhere to go and look for it. These are the four most common slip-ups:

Archiving with no destination: any rule that takes a message out of the inbox has to leave it in a clearly named label or folder. Otherwise, you'll only get it back by searching.
Criteria that are too broad: filtering by a service's domain can put its newsletter in the same folder as a sign-in or payment alert. Filter by the exact address or add words the message must not contain.
Rules that clash: in Gmail, several filters can apply to the same message; in Outlook, the order of the rules matters and there's an option to stop processing further rules. Check what happens when an email meets two conditions.
Rules that only work on one device: some rules in classic desktop Outlook are client-only and run solely when that program is open. If you want them to apply all the time, create them in Outlook on the web.

When to review the Gmail and Outlook filters you already have

Review your list of filters whenever you change job, project or provider, because that's when senders change and old rules start to fail. In Gmail they're in the settings, under filters; in Outlook, under rules.

For each rule, check three things:

Whether the label is piling up unread email: a heap of unopened messages shows you don't read them. Unsubscribe and delete the filter.
Whether the sender still exists: filters for services you no longer use just add clutter to the list.
Whether it has ever hidden something important from you: one case is enough to change the criterion or delete the rule.

Bear in mind, too, where you read your email. If you check your inbox from another app or from a daily summary, find out whether that app reads only the inbox or also the labels and folders: a message archived by a filter may not show up there. Filters work better as a complement to a review habit than as a substitute for one; that's what the method for clearing your inbox is for. There are more practical guides in the email topic section.

Frequently asked questions

Is it better to use labels or folders to filter email?: Labels and folders do the same job when filtering email: grouping a sender's messages together. Gmail uses labels, and a message can have several; Outlook uses folders, and each message sits in just one. What matters is that the filter always leaves the email somewhere you can look for it later.
Can I create a Gmail filter from an email I already have?: Gmail lets you create a filter from an open email: the three-dot menu includes the option to filter similar messages, which fills in the sender automatically. It's worth checking the criterion before saving and applying it to existing messages to see which emails it catches.
Why doesn't an Outlook rule work on my phone?: An Outlook rule that doesn't work on your phone is usually a client-only rule: it's stored in desktop Outlook and runs only when that program is open. Rules created in Outlook on the web are applied on the server and affect all devices.
Is it a good idea to automatically delete email I don't want to receive?: Automatically deleting email with a filter is almost never worth it, because the mistake goes unnoticed: if the criterion catches a legitimate message, it ends up in the bin without warning. For newsletters it's better to unsubscribe, and for unwanted email, mark it as spam so the provider can detect it.