Is there an email filter that isn't trying to outsmart AI? Yes. This one.
Rythm doesn't try to tell real from fake. Rythm is a bouncer. The cover charge creates intention: a sender who pays about four cents to reach you has signaled that the message was worth it to them, whether a human or AI wrote the text.
Content-based filtering (Gmail's machine learning, SaneBox's AI, Proofpoint's classifiers) works by reading the message and guessing whether it's legitimate. As reported by Keepnet Labs, AI-generated phishing is now 24% more effective than human-written (54% click-through vs 12% per StrongestLayer). When AI can write a message that looks exactly like a real person's, content analysis has less to work with. Rythm sidesteps the question. It doesn't filter on content. It filters on intention.
Rythm is a bouncer, not a lie detector.
How each filter handles an AI-written cold email
| Rythm | Gmail ML | SaneBox AI | Proofpoint | |
|---|---|---|---|---|
| How it decides | Did the sender pay the cover charge? | Reads the content and guesses | Reads the content and guesses | Reads the content and guesses |
| Depends on detecting AI | No. Human or AI, treated the same | Yes, getting harder | Yes, getting harder | Yes, getting harder |
| Catches legitimate-looking cold outreach | Yes. Same rule, same gate | Rarely | Sorts, not blocks | Rarely |
| False positives | Near zero (you see the guest list) | Some (hidden in Spam) | Some (hidden in SaneLater) | Some (in quarantine) |
| Annual price | About $21 | Included with Gmail | $84 to $432 | $36 to $82 per user |
Why Rythm is worth considering
- The gate is intention, not prediction. AI or human, if the sender paid, the email comes in.
- Known senders still walk right in. People you already talk to see no friction.
- When a first-time sender pays the cover charge, the money goes to you, so the cost of being wrong is small either way.
- Runs alongside Gmail's or Outlook's native filter. You're adding a layer, not replacing one.
Frequently asked
If AI can write a perfect email, how does Rythm stop it?
Rythm doesn't try to stop AI. Rythm filters for intention. If the sender paid about four cents to reach you, the message gets through. The quality of the prose (human or AI) is irrelevant. What Rythm asks is different from what content filters ask.
Doesn't a determined attacker just pay the four cents?
Attacks that are cheap to scale rely on being free. At four cents per email, sending 100,000 is $4,000. A few attackers will pay; most will not, and the ones who do leave a payment trail.
Do I still need Gmail's spam filter?
Yes, keep it. Gmail's filter is good at bulk, obvious spam. Rythm handles cold outreach and well-crafted individual messages that content analysis struggles with.
What about my contacts who use AI to write emails?
They are already on your guest list because you exchange email with them. The cover charge only applies to first-time senders, so AI-assisted emails from people you know come through normally.
Why doesn't a better AI filter solve this?
A better AI filter still tries to predict what a better AI writer will do. Changing the question (did the sender pay?) sidesteps the problem entirely. Rythm is a bouncer, not a lie detector.
Try Rythm. Your inbox, your rules.
$1.65 a month. Cancel anytime.
Secure My Inbox