I would really like to be able to use labels as proper tags as suggested in the documentation for protonmail. The indication from the docs is that tags are intentionally not a folder, but rather a tag that can be applied regardless of folder. A piece of metadata attached to the message itself. Presumably, given you can filter across all email for that, this is already indexed in some way.

I have a few use-cases for examples. I have labels like "Notifications" and "Ads" to note broad categories of emails. I have labels for email accounts I am migrating to Protonmail, to make it easy to identify what is still using those accounts.

Lastly, I have a label of "Expiring" since there's no way to do filtering, searching, or sorting based on expiration.

First, this would be extremely helpful when troubleshooting Sieve scripts. I initially realized this searching wasn't possible when I was trying to figure out why some emails were falling through the sieve filter in a way that resulted in being tagged with both Ads and Notifications -- which shouldn't happen. I wanted to search for emails that have both to begin troubleshooting but couldn't.

I can search for one, but because of the UI limitations I cannot see in the index which ones also have the other tag, because I can only see one tag and then +x for how many other tags are present. So I have to click through one at a time to find examples.

I can't even filter Notifications into a folder instead and solve it that way, because searches are only against "All Mail". I can limit to a Folder, but then I can't search for a label.

My plan for tagging anything sieve marks for expiration with Expiring was to be able to review this. To view key combinations like "folder:Invoices label:Expiring" or "label:Notifications label:Expiring" to do a quick scan to see if I needed to cancel expiration or otherwise take action on any of those. Not to mention checking to make sure sieve didn't flag any of them incorrectly.

Next example is that I filter things like communication from businesses that I buy products from into their own folder, along with related communication. The ones that are connected to actual shipping and delivery I add a label of "Deliveries" to. I don't sort every company to its own folder, but I do separate out some of them, and I'd like to be able to quickly view just the delivery notifications from a given vendor like "folder:Shopping/Etsy label:Deliveries" and cannot.

Lastly I filter finance related messages to a folder tree organized by year. The ones that are tax-related are tagged as "Taxes". Here pretty soon I'm going to have to get my tax prep going and I had expected to be able to do something like "folder:Finance/2025 label:Taxes" and easily see all of the messages connected to that. I can somewhat fake this one out with a date range for messages combined with the Taxes label -- but it's still a good example of how I'd would use it.

HTH

Please, do this feature as quick as possible. It's a shame that this ideia is here since 2019, almost 5 years and no response from the Team. Estou começando a me arrepender de ter assinado por um ano o Proton Ultimate.

I was really surprised when I found out that I cannot filter/search/select multiple labels at once. I've tagged mails with several labels to indicate their status and belonging and then I discover that I can't filter for them. I understand that search even for metadata in encrypted content can be difficult to implement but it's possible to filter for a single label so I assume that the metadata is available (maybe in encrypted form or at least on the client).

I was about to upgrade before I found out labels are so extremely limited in functionality, including this.

Critical search function. Without it, I may just have to go back to other email options.

It's been over 5 years since this request was created. Why this critical functionality hasn't been implemented?

- allow to search for messages with no label

Another vote for this feature. I migrated everything from Google to Proton and really miss this feature.

It would be great to be able to select multiple labels in the left sidebar.

Also, please allow us to save these customized searches for rapid searches in the future.

I love Proton, but it's crazy that this doesn't exist. It doesn't seem like it should even be that hard to implement.

the lack of being able to search (or filter) by multiple labels really eviscerates the value of labels. oye!

Just signed up for a paid family account, and began the import process... the lack of this ability is making it incredibly difficult to manage the transition.

Same thought as Jacob mentioned earlier here, I find it utterly shocking to have implemented only single label searches. Many systems share the same common point, labels are useful for "multi dimensional" filtering. Otherwise it seems like a folder, you've implemented this as if they were folders.
I'll give a meaningful example. An email can be related to 'support' being requested from your 'bank' support team. And another be related also to a 'support' to a 'social network' platform.
You're then forcing us to implement 2 labels: 'banking/support' and 'social media/support'
Not ideal to deduplicate and it can increase considerably the admin task to manage your emails.
And because of that, I can't switch to Proton and consider it as a production ready email platform.

I was shocked that you can only search on one label.

You built a label system why have it be gimped. What's the point of assigning multiple labels if I can't search by a combination of them?

It is also a critical part of the onboarding (import) stage to allow for properly manage issues that come up.

Absolutely critical, especially when a lot of power users are used to google.

See their search docs: https://support.google.com/mail/answer/7190

Even if you can't implement search syntax, at least try to keep up with functionality.

This is a must have. I'm finding it not possible to organize my email after migration.

Actually, looking a little more into the ideas, I cannot believe that this only has 163 votes. I would give it all mine if I could.

Why have labels if you cannot make search in several labels and/or folders? I often want to find my mails in one folder with one or more labels.

have seen this all over the place requested many times for many years. AND saw a message saying the API actually already supports it, so it is just a front end implementation.

As per all the comments below, labels are no more useful than folders without being able to use AND with them - otherwise there's point assigning multiple 'virtual folders' (ie labels) to them.