Inbox fee makes strangers pay for their cold emails!

Set up a fee on those polluting your inbox! Make marketers, salesmen, and recruiters pay before you spend your attention on their mail.

Get it on Google Play
InboxFee - Make strangers pay for their cold emails | Product Hunt Embed

Clean up your inbox, and get paid for your attention!

Everyone treats your inbox like it's free. Salesmen, marketers, recruiters, and others are sending you cold emails every day, adding clutter to your inbox. They trick you into opening their mail with clickbait headlines and then follow up aggressively if you ignore them. That's not right! Your attention is not free, and now you have a way to get compensated.

Download the app

It's free, simple, and easy to control

Connect to your inbox

It's private, your data never leaves your device. Gmail is supported, Twitter coming soon.

Send invoices

Send inbox fee invoice in reply to the mail from a stranger, in just one click.

Get paid

Get notified if the fee is paid, otherwise just ignore the cold email.



Inbox privacy

Data from your inbox never leaves your device. You can be sure your private communication is safe and not leaking to us or third parties.

Anonymous payments

The inbox fee payments don't reveal your identities. The new Bitcoin Lightning payment network makes it possible.

Flexible fee amount

You can set your inbox fee to as high as several dollars, or as low as several cents. The new payment network can handle it.

Automatic invoicing

When you're confident in our cold email detector, just turn auto-invoicing on and you won't need to confirm every new invoice.

Language detection

If you get cold mail in different languages, the app will automatically choose the invoice template in the appropriate language.

Open invoicing protocol

The inbox fee invoices are sent using an open format and protocol, you are not locked to the InboxFee app if other similar apps arise.

Open payment network

Lightning Network is an open payment network for Bitcoin. Payers can use any wallet and are not locked to using the InboxFee app.

Non-custodial payments

If you have your own Lightning Network node, you can use it directly to generate invoices and accept payments. Coming soon

Pay with credit card

InboxFee wallet can be refilled using a credit card, and so inbox fee payers are not expected to own any Bitcoin upfront. Coming soon

All inboxes

All email providers and social networks will eventually be supported by the InboxFee app. Coming soon

All platforms

In addition to the Android app, an iOS version is in the works. Desktop and server versions for business purposes are next. Coming soon

All languages

Many of our users are multi-lingual, and so making the app interface usable all over the world is our priority. Coming soon


Get the app

Get it on Google Play


Download on the App Store

Coming soon


Frequently Asked Questions

  • Why should I pay a fee for sending someone an email?

    Your mail consumes people's time and attention. We have accepted unsolicited email as a fact of life simply because there was no efficient way to charge for it. However, modern payment networks make it possible to process small payments and not risk losing your inbox privacy. We expect that monetary compensation for cold emails will now become the norm, and will actually be a psychological relief for both sides: if you paid a fee, you can get straight to business instead of tricking the recipient into opening your email and getting them annoyed.

  • InboxFee uses the new Lightning payment network that allows you to transfer small amounts of Bitcoin in a fast, secure and private way. No other payment system, including credit cards or Paypal, provides all the attributes required to support the inbox fee use case. But don't be scared of Bitcoin: the only reason some people dislike it is because it's price in USD is volatile, but inbox fees are quite small (up to several dollars), and so your financial risk is minimal. Maybe the InboxFee app is your opportunity to play safely with Bitcoin and learn what it really is...

  • InboxFee app works on your device and only talks to your inbox from your device. The data from your inbox (your contacts and contents of your mail) never leaves your device and is never transferred to our server or third parties. The only thing our InboxFee server does is provide a simple custodial Lightning Network wallet for you, to simplify your onboarding into the payment network. If you host a Lightning Network node, you can bypass the use of our server altogether and use your node directly, and thus get the ultimate privacy. In short: your inbox is safe and your privacy is preserved!

  • We do forward your payments of inbox fees to the Lightning network if you use our default custodial wallet. However, we do not require personally identifiable information (like an email) from you and your peers and thus cannot know who is paying to you, and who you pay to. And when we release our non-custodial wallet as a mobile app, or if you use your own Lightning node, you can bypass our servers altogether and be 100% sure that none of your data is ever leaking to us or third parties.

  • If you use our default custodial wallet to accept inbox fees, then we are charging a 10% commission on every payment you receive. But we take zero commission when you withdraw your Bitcoin from our custodial wallet (we pay all payment network fees). This way we incentivize you to learn about Bitcoin and Lightning and to switch from our custodial wallet to your own non-custodial one, which is a more secure and private way to charge inbox fees. Eventually, we might start charging for the app itself, but for you - our early users - the app will always stay free!