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Check If Email Exists

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Re: Check If Email Exists

#221

Earlier quoted context omitted.

That’s you (and the large part of HN who doesn’t know anything about normal users). When GDPR came into effect, we even had people write us that they were annoyed having to reconfirm, as obviously they still wanted our newsletter.

Some people want to receive marketing emails. The exact same emails are spam to the rest of us. If you default opt-in users and don't make blanket unsubscription from all marketing emails easy (and make the clear distinction [both internally and externally] between emails regarding the existing functionality of products/services that we've already paid for and emails to ask for more revenue from us, which includes co…

I have a common name first year/generation gmail account. The volume of mail I receive that I didn't solicit is mind-boggling. Not just spammers, but it's obvious that people have saved the wrong address in their browser suggestions, and that people give it out when asked for an email addresses at retail. Disney employees, California private school parents, iPhone receipts and apple IDs. Taxes, warrants, bail bonds, social security information. People are f'ing stupid when it comes to email.

Everything should require a confirmation before you assume it's valid. Not because it doesn't exist but because it might not be who you think it is.

Re: Check If Email Exists

#222
post #90
post #70

Earlier quoted context omitted.

This isn’t just good against spam. If there’s a data breach on the site, it’s another layer of insulation against you and other accounts you own. It’s close to the equivalent of Apple allowing you to sign up to services using one of their anonymous emails — there’s clearly demand for people to want to keep their emails from being thrown around everywhere.

Wouldn't someone be able to reverse engineer the pattern? I assume everyone is doing some variation of so someone can try to figure out your other email addresses for other sites. Although I don't know if that's worth the time investment.

Right. The method has it’s own flaws, but it’s still another layer of insulation. Someone getting your email off a large user data breach is less likely to pick out your name and attempt to reverse engineer that pattern specifically for you, unless it is a targeted attack against you. For most people, that’s a highly unlikely scenario

Re: Check If Email Exists

#223
post #196

Earlier quoted context omitted.

I receive a lot of fake user signups on the web tool I publish for free. These users (bots?) sign up using fake email addresses, but putting a captcha does not help much. I send a confirmation email to these users to make sure they exist, but if the email address does not exist, sending that confirmation email hits my account's deliverability (spam) score as it generates a bounce which my email sender provider does n…

I think what this is telling you is that users don’t value giving you their email address for your free tools. They know why you want their email address, and they don’t want that, but they do want your tools. Maybe it’s time to charge money for those tools or change models? Maybe not give access until the email address is confirmed? Worth considering I guess. Idk the details. I do this all the time. Ads and malpract…

You seem to be assuming “a lot of fake user signups” == “few real user signups.” OP only said the first. For all we know they also get plenty of real ones.

Re: Check If Email Exists

#224

Why this is not a library instead of hosted api? Why do we need to run this as a service? does it come with its own DB & all?

it's both; the OSS library is usable freely and the hosted version is auto-generated by https://saasify.sh

> does it come with its own DB & all?

Also, there's no DB. Each verification is done in real-time.

Re: Check If Email Exists

#225
post #196

Earlier quoted context omitted.

I receive a lot of fake user signups on the web tool I publish for free. These users (bots?) sign up using fake email addresses, but putting a captcha does not help much. I send a confirmation email to these users to make sure they exist, but if the email address does not exist, sending that confirmation email hits my account's deliverability (spam) score as it generates a bounce which my email sender provider does n…

I think what this is telling you is that users don’t value giving you their email address for your free tools. They know why you want their email address, and they don’t want that, but they do want your tools. Maybe it’s time to charge money for those tools or change models? Maybe not give access until the email address is confirmed? Worth considering I guess. Idk the details. I do this all the time. Ads and malpract…

You seem to be assuming there's no reason these tools need a login system at all. Assuming they do and they're storing some kind of state or data for the user, how do you handle forgotten passwords if the user can't receive an email? A second free tier for people who can't be bothered to add a recovery email is too much work for a tool that's free anyway.

To the parent: Just send a validation email during the onboarding process. Don't create the account until they validate. And DO rate limit the number of these sent to any given address and the number of signup attempts by IP / fingerprint. Captchas are also good, but just for slowing fakes down.

Re: Check If Email Exists

#226
post #43

Earlier quoted context omitted.

Mailcheck is also helpful to catch things like "user@gnail.com" and other common typos when the user types it in: https://github.com/mailcheck/mailcheck Fork modified for React: https://github.com/eligolding/react-mailcheck#readme

I somewhat lol'd when the demo allowed "user@gnail.com" just fine. Guess kickstarter isn't using mailcheck anymore. Looks like it's an open issue: https://github.com/mailcheck/mailcheck/issues/179

Oh, yeah, that's not good. Not sure why they didn't just repoint to the suggested https://codepen.io/ianneub/pen/BajKKBy demo.

Re: Check If Email Exists

#227

Earlier quoted context omitted.

I think what this is telling you is that users don’t value giving you their email address for your free tools. They know why you want their email address, and they don’t want that, but they do want your tools. Maybe it’s time to charge money for those tools or change models? Maybe not give access until the email address is confirmed? Worth considering I guess. Idk the details. I do this all the time. Ads and malpract…

You seem to be assuming “a lot of fake user signups” == “few real user signups.” OP only said the first. For all we know they also get plenty of real ones.

Weird. Same exact 5-word opening I was typing. I didn't see your post until I posted mine.

Re: Check If Email Exists

#228

Earlier quoted context omitted.

CAN-SPAM regulates "sending electronic mail messages". Connecting to an SMTP server to ask it if an address exists doesn't sound like that to me, but IANAL.

majority of mail servers do not support VRFY command, that is why the generic method of checking mail box is trying to send message (via MAIL FROM + RCPT TO) and breaking the sending halfway through

Okay, but that still sounds to me like taking an overly technical view. I doubt the courts will consider it sending an email if an email isn't received.

Re: Check If Email Exists

#229

The SMTP way of checking if an email exists is on the wrong side of CANSPAM, beginning the sending process to check an address is specifically addressed. And this assumes you didn't systematically "guess" the address.

Can you point out where in CAN-SPAM checking an address is specifically addressed? I haven't heard of this and a quick perusal of CAN-SPAM doesn't turn this up anywhere

Re: Check If Email Exists

#230

Earlier quoted context omitted.

I think what this is telling you is that users don’t value giving you their email address for your free tools. They know why you want their email address, and they don’t want that, but they do want your tools. Maybe it’s time to charge money for those tools or change models? Maybe not give access until the email address is confirmed? Worth considering I guess. Idk the details. I do this all the time. Ads and malpract…

You seem to be assuming there's no reason these tools need a login system at all. Assuming they do and they're storing some kind of state or data for the user, how do you handle forgotten passwords if the user can't receive an email? A second free tier for people who can't be bothered to add a recovery email is too much work for a tool that's free anyway. To the parent: Just send a validation email during the onboard…

> Just send a validation email during the onboarding process. Don't create the account until they validate.

This is literally the same thing the person you're replying to suggested.

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