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Check If Email Exists

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Re: Check If Email Exists

#171

Post by jitbit »

3np wrote: post #121

Interesting tool, but there are some really concerning dark antipatterns here that I really despise: Is the address provided by a known disposable email address provider? Is the email address bound to a known free email provider? Does email address under test hide a honeypot? What are the legit use-cases for this? To be sure you can force spam on your users and identify them as ad-targets?

RE: use case

In our SaaS we enforce slightly stronger limits for trial accounts who sign up from free/disposable emails. User is Gmail? Well, sorry, +XX to "spam score". They will probably use our system for spamming.

Re: Check If Email Exists

#173

Post by InfiniteRand »

mr_toad wrote: post #47
contravariant wrote: post #26

Earlier quoted context omitted.

Though if we follow this logic to its conclusion then using and distributing a program that cracks a trial version of software doesn't shouldn't be a copyright violation. That said I would be interested if anyone could clarify to what extent a copyright license has any legal power if you're not distributing anything.

> to what extent a copyright license has any legal power if you're not distributing anything. Simple: no license, no copy. It doesn’t matter how many copies you make, you still need a license. The “defence” of “I didn’t agree to the license” is basically admitting knowing and wilful infringement.

I don’t think the act of copying could be illegal since backups are a thing

Re: Check If Email Exists

#174

Post by gorgoiler »

GitHub issues like this one warm my heart:

https://github.com/reacherhq/check-if-email-exists/issues/91

Identifying something that needs doing, especially when you have no idea how to do it, is a bold skill.

Too often have I seen engineers be reluctant to open an issue because they don’t know how to implement it, technically. I still do it, myself. If you need it then you’ll find a way.

The converse is also true: losing focus by filing tasks and procrastinating on features because you know how to build them, not because you actually need them to move your business / project forward.

Re: Check If Email Exists

#175

Post by BiteCode_dev »

reid wrote: post #30
Cyberdog wrote: post #8

Could someone spell out a use case for this? One that comes to mind would be validating that a mailing list doesn't have any outdated email addresses in it, but couldn't that be determined by just checking for a bounce when a message is sent to it? I tried to sign up for SiriusXM the other day, and though I could create an account with my .pro email address, I couldn't actually sign up for service with that same addr…

I bought a new car a few years ago and I was unable to enter my .life email address into the SiriusXM registration form in the car. Had to use a .com address :(

Same, got a .email tld, and regularly get rejected.

Forget about AI and self driving car, we can't even get email validation right in 2021.

Re: Check If Email Exists

#176

Post by etripe »

tlogan wrote: post #82
jlawer wrote: post #48

Earlier quoted context omitted.

The use case is marketing email. Sending to non-existent addresses can radically affect deliverability. If the address is to a large host, then they will use reaching invalid email addresses as evidence that you are not keeping to best practices. They will throttle deliverability, and possibly reject email. If your sending to an invalid host, then your mail sending provider (if your using one) may consider you a bad…

This is not for “marketing emails”. This is for spammers.

I don't know if it's always spam, but it's up the same creek as trying to brute-force your way into someone's heart.

Re: Check If Email Exists

#177

Post by mkl »

X-Cubed wrote: post #132
spondyl wrote: post #62

Earlier quoted context omitted.

I have my email with Fastmail too and issuing a RCPT TO command via telnet returns the following: > 451 4.7.1 : Recipient address rejected: Temporary deferral, try again soon

The library identifies itself to the mail server with a from address of "testing@example.com". It's probably a good idea to use an email address you own as the from address if you want to use this in production, eg: "testing@mycorp.com", to avoid this grey-listing.

Indeed:

  {
    "input": "testing@example.com",
    "is_reachable": "unknown",
    ...
  }

Re: Check If Email Exists

#178

Post by aorth »

reid wrote: post #30
Cyberdog wrote: post #8

Could someone spell out a use case for this? One that comes to mind would be validating that a mailing list doesn't have any outdated email addresses in it, but couldn't that be determined by just checking for a bounce when a message is sent to it? I tried to sign up for SiriusXM the other day, and though I could create an account with my .pro email address, I couldn't actually sign up for service with that same addr…

I bought a new car a few years ago and I was unable to enter my .life email address into the SiriusXM registration form in the car. Had to use a .com address :(

I had a similar experience with LG. You need a developer account in order to install applications on webOS TVs. I successfully registered on the LG Developer portal with something like myname+us.lgaccount.com+2021-07-01@mydomain.com, but I couldn't log in on the TV with that email address. Had to register again without the plus signs.

Re: Check If Email Exists

#179

Post by yreg »

3np wrote: post #121

Interesting tool, but there are some really concerning dark antipatterns here that I really despise: Is the address provided by a known disposable email address provider? Is the email address bound to a known free email provider? Does email address under test hide a honeypot? What are the legit use-cases for this? To be sure you can force spam on your users and identify them as ad-targets?

They even link honeypot to spamtrap.

https://en.wikipedia.org/wiki/Spamtrap

Re: Check If Email Exists

#180

Post by baobabKoodaa »

I tried this on my email address and it didn't work. SMTP error "permanent: 5.7.1 : Helo command rejected: ACCESS DENIED. Your email was rejected because the sending mail server seems to be impersonating another mail server (gmail.com)"
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