Captchainbox - Make senders work to get into your inbox
Log inStart free
Stop AI cold spam
Make unknown senders work to get into your inbox.<br>Stop AI spam from flooding your inbox and calendar. Unknown senders solve a CAPTCHA or pay a fee to get in. Trusted contacts get through as usual.<br>Connect your EmailGmailOutlookOtherSoon
See how it works<br>7-day free trial · 5-minute setup · Archived, never deleted
captchainbox.com/verify<br>Prove you are human
I am human<br>Deliver my message
MailSearch mail
Live
ComposeInbox3<br>Archived2<br>Trusted284
InboxArchived 2Trusted 284<br>SC<br>Sarah Chen<br>now<br>sarah@designco.com<br>Re: new design direction
Checking sender…Delivered to your inbox
Inbox · just delivered<br>3 items<br>SC<br>Sarah Chen<br>Re: new design direction
now<br>Stripe<br>Receipt for your subscription
6m<br>Linear<br>PR #842 was merged
1h
Sarah
Verified sender<br>2 awaiting verification
Proceedings are donated to
Pooled and donated annually, 50/50. See the ledger.
Built for inboxes overwhelmed by AI outreach<br>AI cold outreach is nearly free. Make senders work for your time and attention.<br>Spam filters catch the obvious, but mass-customized outreach gets through. You miss what matters and drown in what you didn't ask for.
Step 01<br>Sign in with your email provider.<br>Captchainbox scans your conversation metadata. We never read your messages. We build a trusted sender and domains list for you.<br>Sign in with your email provider
Gmail connected<br>you@gmail.com
Scanning sent history…0%
Analyzed<br>2,847
Trusted<br>284
Status<br>Active
div:first-child]:order-2">Step 02<br>Every sender checked silently.<br>For every new email Captchainbox checks the sender against your trusted contacts. Unknown senders are archived (never deleted) and sent a verification link. Introductions through trusted contacts get through.<br>See how filtering works<br>Inbox protectionLive
Step 03<br>Senders show they are worth your time and attention.<br>Unknown senders verify through a CAPTCHA or pay a small fee to show they are relevant to you. They complete the verification and their email is delivered to your inbox. Payment fees get pooled and donated.<br>See the verification flow in action
captchainbox.com/verify/···
Inbox verification<br>This inbox uses a quick CAPTCHA. Complete it to get your message delivered.<br>Recipient picked: CAPTCHA<br>Complete the CAPTCHA
I am human<br>Deliver my message
You're verified<br>Your message is on its way to their inbox.
Pricing<br>Simple pricing to get back your time and attention.<br>Free 7-day trial, no credit card required.
Per inbox<br>$5/ month<br>7-day free trial included
Real-time inbox filtering<br>Calendar invite protection<br>Trusted circle from sent history<br>Introduction detection via CC<br>Configurable filter rules<br>Custom auto-reply templates<br>Emails archived, never deleted
Start free trial
Take back your inbox.<br>Set up in 5 minutes. Free to get started.<br>Connect your emailGmailOutlookOtherSoon
Curious what senders see? Send me an email and see the verification flow yourself.