Client mail that nobody else reads.
Klar filters spam inside Apple Mail, on your own machine. The extension that reads your inbox has no network permission, so classification sends no client correspondence to a vendor.
Cloud filtering is allowed. It is also yours to police.
Rule 6.3 of the SRA Code of Conduct requires you to keep the affairs of current and former clients confidential. Nothing in it forbids a cloud spam filter, and any vendor implying your duty makes their competitor illegal is selling, not advising. What the rule does mean is that routing client mail through someone else's servers is an outsourcing decision you own.
The SRA's own guidance asks firms that outsource to consider whether the arrangement adequately protects confidential information, and notes that clients may not have agreed to their affairs being reviewed by unregulated third parties, possibly in another jurisdiction. That is real work: diligence on the vendor, terms that bind it, a view on where the servers are, and a judgement that stays yours after you sign.
SRA guidance: confidentiality of client informationThe filter runs where the file already sits.
Klar is a Mail extension. It scores each message on your Mac as it arrives, in the same place the correspondence already lives, without uploading it. No filtering provider to select, no terms to negotiate, no jurisdiction to assess. Not because we did that work for you, but because it never starts.
The part of Klar that reads your mail is an Apple-sandboxed Mail extension shipped without the network entitlement. It is not that we promise not to send your mail anywhere. It is that macOS refuses the connection, because the permission was never requested. Classification happens on your Mac, instantly.
What that means in practice
- No network access
- The free App Store app and its Mail extension ship without the network entitlement. macOS refuses any connection they try to open. This is a permission the app does not hold, not a policy it promises to follow.
- The model ships with the app
- The classifier is a multilingual transformer inside the app bundle. Nothing is fetched when a message arrives, so it works the same on a train as it does in the office.
- No account
- There is nothing to sign up for and no licence server the free app calls. Unless you contact us or choose to send an Email report, we do not know who you are.
- The engine is open source
- The scoring engine is AGPLv3. Your IT people do not have to take our word for any of this. They can read it, build it, and watch what it does.
Questions your compliance officer will ask
What happens when Klar gets a client's message wrong?
It lands in Junk on your Mac and you move it back. The mistake stays on your machine: no copy was sent anywhere and nothing about the message was reported to us. With Klar Plus, moving it back also teaches the filter, and both the correction and the model it produces stay in a sandboxed container on your Mac.
Can we roll this out across the firm?
Not centrally, and not today. Klar is a free Mac App Store app that each person installs, with no account and no admin console, which is the same property that makes it hold nothing about your firm. If the firm runs its own mail servers and wants filtering before delivery, Klar Pro is a Postfix milter in early access, and that is a conversation rather than a download.
Does filtering send anything off the machine?
No. The free App Store app and its Mail extension have no network permission. If you choose Email report, Klar opens an editable draft in your own mail app; nothing leaves until you send it. Do not include confidential correspondence unless you are authorised to share it. Klar Plus, the paid companion you install yourself, separately uses the network for its licence, model and version checks. None carries your mail. The full list is on the local-first page.
Do we need a data processing agreement with you?
That is a question for your own counsel, and it depends on which part of Klar you run. Routine filtering sends us nothing. A user who sends an Email report may share selected messages, diagnostics and a removable monthly usage summary; our privacy policy explains what we then hold. Decide whether staff may use that report action with confidential correspondence.
What we are not claiming.
We are not offering legal advice, and a spam filter does not make anyone compliant. Your obligations are yours, and your bar, your regulator or your DPO is the right place to test them. What we can tell you is exactly where the software runs and what it is permitted to do, which is the part most vendors leave you to infer.
We are also not claiming perfect filtering. No filter is, and any vendor quoting you a single accuracy number is quoting a number from their corpus, not your inbox. What we will say is that being wrong about a message on your Mac and being wrong about it on someone else's server are not the same kind of wrong.
Read the whole local-first argumentTry it on the inbox you cannot risk.
macOS 14 or later, Apple Silicon. No account, no cloud classification, no setup. It filters inside Apple Mail on your Mac.
