blockchain email spam

How Blockchain Can Fight Spam and Why it Isn’t a Terrible Idea

Recently there’s been a strong backlash within the tech community to the concept of using cryptocurrencies and the blockchain to fight spam.

The main two startups copping flack right now appear to be and Bitbounce.

For instance, nine months ago @rachelburger on steemit wrote a scathing review of bitbounce. Then earlier this year, BuzzFeedNews tech report Ryan Macc tweeted this angry tweet after he hit the paywall:

A month later The Next Web posted an article with the title “Using cryptocurrency to fight spam is a terrible idea”.

Fair to say there’s been a fair bit of hostility in the tech community towards the idea of fighting spam with cryptocurrency and/or the blockchain.

But is this criticism founded?

Is the idea of using the blockchain/cryptocurrency to address the problem of email inboxes overflowing with spam really such a terrible idea?

Or is it more just that and Bitbounce miss the mark and need some refining?

It is only natural that every time someone proposes a solution to spam that their proposal is met with a healthy skepticism. Think back to 2004 when Bill Gates famously stated that email spam would be dead within two years.

His claim was met with the same healthy skepticism that is eager to greet and bitbounce. And it wasn’t unfounded. One and a half decades later and we’re still dealing with the problem of spam.

Let’s not let our Skepticism Cloud our Judgment

While a lot of people know about Gates’ ambitious declaration, few know about his and Microsoft’s plan to achieve it. And while it is clear that their plan did little to stem the barrage of unsolicited emails, it is worth exploring how they thought they would be successful.

Ultimately, their plan was to monetize emailing. The key reason why this plan didn’t eventuate was that the technology to enable monetizing email wasn’t ready 14 years ago.

Combatting email spam through monetization isn’t in itself a bad idea.

Compare the amount of email spam to the amount of SMS spam. Despite the high number of mobile phone users, the cost involved with SMS has effectively made receiving unsolicited text messages a rare occurrence. Even though the cost of sending a small number of text messages is minuscule, spammers rely on sending vast amounts of messages. On the SMS platform sending such a volume renders the exercise commercially unviable.

The Current Approach

The SMS platform isn’t the only one that has escaped the level of spam currently plaguing email.

Think about messaging spam on social networks such as Facebook or Twitter. These platforms aren’t subject to the same costs of SMS, yet social networking spam is nowhere near such a problem as email spam. This is in large part due to social networks being centralized platforms with the companies behind them monitoring who is sending messages to who. Spammers can then be quickly identified and blocked. Obviously this process is far from perfect, that’s why you still receive the occasional spam message.

That said, inbox service providers (ISPs) and are centralized and act as gatekeepers to who can send you email too. However there is a key difference in the nature of email compared to messaging on social media. And therein lies the reason we still have email spam.

Typically you’ll only message a maximum of a couple of dozen people on, say Facebook Messenger, at least semi-regularly. In contrast, the number of senders you get emails from on a semi-regular basis is likely much more.

The nature of these contacts are also vastly different. On Facebook Messenger you are getting messages from your partner, friends, and family. And even though email is fundamentally personal one-to-one messaging too, we have opened it up to a plethora of marketers and organizations. Now you’re typically having banks emailing you your monthly statement, monthly newsletters you’ve subscribed to, work emails, LinkedIn/Facebook/Gmail terms of service change announcements. Perhaps also the odd message from your grandmother who still hasn’t moved across to social media.

All these differences make it a lot harder for ESPs such as Gmail and Outlook to detect spammers before they reach your inbox. It’s much harder to differentiate a spammer from an impersonal yet important email compared to detecting spam in amongst personal messages from friends and family.

That said, current email spam filters actually do a reasonable job at filtering spam. Just check your spam folder and imagine if you were getting all those emails straight to your inbox instead. Problems tend to occur when your email address has been leaked to unscrupulous senders acting as though you did indeed sign up to their emails. Unsubscribing from these lists can be a pain.

This is why a better solution is needed.

Thankfully, cryptocurrencies and the blockchain technology they’re built upon have opened up new possibilities for dealing with email spam.

Staking Crypto

One option for using the blockchain to reduce spam is to reward good email marketing while punishing spam and lower quality email campaigns. This could take a number of different forms. Ultimately though, they all boil down to harnessing individual users’ abilities to detect spam.

Ethereum’s creator and co-founder, Vitalik Buterin earlier this year talked about one possible take on this through using cryptoeconomics. His idea was essentially to have users stake collateral in the form of cryptocurrency into either upvoting or downvoting posts on platforms such as Twitter. Later when a consensus is achieved users would be rewarded for upvoting a post the consensus determined not to be spam and also rewarded for downvoting what the consensus determined to be spam. The reverse would also be true where users are punished by losing their cryptocurrency for voting in contradiction with the consensus.

By introducing an economic incentive for ranking content, more users would be encouraged to do so.

While Buterin’s proposal mainly centred on social media posts as a means of also fighting fake news, his concept could be applied to emails too. An additional issue that email presents though is that individual emails are private. Trying to gain any consensus on whether an individual email is spam without making it public for all to see doesn’t appear to be possible. Instead of ranking individual emails though, email marketers could be assessed instead. That way it is not so much individual emails being up or downvoted, but rather email marketing campaigns being voted on as a whole.

Given the current setup in Sendy where marketers stake a set amount of points to a campaign to be distributed to engaged subscribers, a solution could be that if 50% or more of openers mark the email as spam a portion of the staked amount is burned. This doesn’t incentivize receivers to mark emails as spam as they receive zero benefit. However it disincentives marketers as if they do send spam, they’ll have less points available to incentivize subscribers to engage with emails. It’s very much a theory, but it is a way cryptocurrency can be used to fight spam and without the friction of other methods like the current solutions I’ll outline below.

A high-friction solution that hasn’t worked

The advent of Bitcoin and the blockchain that came with it has also revived attempts to monetize email again. Even though the Bitcoin network may not be suited to this particular application, the fundamentals unpinning blockchain technology have lead to multiple startups exploring this idea.

This is where micropayments and whitelisting come in through Bitbounce and

With both Bitbounce and, any sender you pre-approve can continue to email you as usual. The difference is when someone who is not on your whitelist tries to email you. Instead of the email going through as usual, the email bounces and the sender receives a message telling them if they want to email you, they need to cough up.

Personally, I agree with the criticism against Bitbounce and here.

The process of manually whitelisting all your known email contacts is very hassle-some on behalf of even a light email user. For any kind of serious emailer this process will take, at a minimum, hours. Even then it’s almost guaranteed that you’ll miss one or two important contacts who will no longer be able to get through to your inbox.

For people to adopt any new technology the transition process must be as seamless as possible. At the very least, the benefit the new technology promises to deal must be greater than the cost associated with migrating. The time saving from no longer having to deal with spam landing in your inbox is likely too little compared with the hours of whitelisting and then having to deal with important emails that fail to make it on the list for people to take up this method.

But while these applications of the blockchain and crypto to fight spam miss the mark, we must not disregard the massive innate potential these technologies hold.

As with the broader transition from Web 2.0 to Web 3.0, services that manage the transition seamlessly for the user will be the ones most likely to succeed. This is partly why Vitalik’s proposal of staking crypto represents a far better implementation.

I strongly believe in the potential that the blockchain has to revolutionize all different kinds of industries. Email being no exception. And while we are yet to see a proper implementation of crypto or the blockchain to address email spam, it is only a matter of time before we do.

Want to learn more about Sendy? We’re the team behind Sendicate and Smartrmail, and last year helped over 7,000 businesses send over 1 billion emails. We’re working to improve engagement with marketing emails and reward subscribers for their valuable attention. If you’re interested in the project, check out our site

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