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Check If Email Exists

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Re: Check If Email Exists

#41

Post by makeitdouble »

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 One that comes to mind would be validating that a mailing list doesn't have any outdated email addresses in it, but couldn't that be determined by just checking for a bounce when a message is sent to it?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 am not sure there is any clear legitimate use for deep validation (beyond checking for syntax). If you are providing a valuable service to a customer, wether it's a catch-all or free mail shouldn't matter to you.

Now, if you are buying lists here and there to spam the hell out of it, the bounce rate would flag you very quick and you'd need to find another smtp provider every week. This service would be your life line.

Re: Check If Email Exists

#42

Post by adamparsons »

My email address reachability is "unknown", its a fastmail hosted account. Quite a commonly used service.

Is an unknown classification supposed to be treated as "I don't know, probably safe" or "I don't know, probably don't accept it" ?

Re: Check If Email Exists

#43

Post by tyingq »

akcreek wrote: post #19
tyingq wrote: post #14

Earlier quoted context omitted.

>but couldn't that be determined by just checking for a bounce when a message is sent to it The fewer times you bounce, the better your chances of not being marked as a spammer. This could also be useful for an ecommerce site, where you want to be able to easily contact the buyer if there's a delay, address correction needed, etc. People typo their own email at a rate that's surprising.

I use email validation via MailGun for exactly this purpose with a productized service business. If we don't have a good email, then we can't deliver the service once complete. That leads to angry customers, even if the issue was a typo when they created the account. Easier to try and catch it during signup rather than at the time of delivery when emails start bouncing and you have no way to get ahold of the person.

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

Re: Check If Email Exists

#44

Post by adamparsons »

adamparsons wrote: post #42

My email address reachability is "unknown", its a fastmail hosted account. Quite a commonly used service. Is an unknown classification supposed to be treated as "I don't know, probably safe" or "I don't know, probably don't accept it" ?

    {
      "input": "***redacted***",
      "is_reachable": "unknown",
      "misc": {
        "is_disposable": false,
        "is_role_account": false
      },
      "mx": {
        "accepts_mail": true,
        "records": [
          "in2-smtp.messagingengine.com.",
          "in1-smtp.messagingengine.com."
        ]
      },
      "smtp": {
        "error": {
          "type": "TimeoutError",
          "message": "future has timed out"
        }
      },
      "syntax": {
        "address": "***redacted***",
        "domain": "***redacted***",
        "is_valid_syntax": true,
        "username": "***redacted***"
      }
    }
I'm going to guess that fastmail has blocked you lol

Re: Check If Email Exists

#45

Post by cstrat »

reid wrote: post #24
rudyfink wrote: post #22

Earlier quoted context omitted.

Would you mind sharing your experience on how well that has worked for you? Has the complexity of maintaining different addresses been a problem? I ask because it is something I have always thought about, but I suppose I kept hoping a service would come along and magic the solution for me. Kudos on making it happen!

Not OP, but I just accept wildcard *@mydomain and give out a unique name for every business. Works very well and I blocked a few businesses by which do not allow for opt-out and/or shared my address with others. This is easy to do with the Alias feature of FastMail.

Yeah I do the same thing with FastMail - its awesome.

Here is a recent story where this came in handy.

I recently had a spam phone call from someone fishing for personal information, using a 'survey' as cover. During the call I learned that they had my email address as 'ledger@xxxx.xxx'. This must have come from the Ledger data breach (https://www.ledger.com/message-ledgers-ceo-data-leak). This made the call even more nefarious than I originally thought... nothing I can do, they have that email address and my personal number. Just made me more aware of what is going on.

Re: Check If Email Exists

#46

Post by lqet »

> The details of this [reachability=]"unknown" case can be found in the smtp.error and mx.error fields.

Indeed they can, my mail server seems to block the service because it already appears on multiple spam lists.

Re: Check If Email Exists

#47

Post by mr_toad »

contravariant wrote: post #26
jchw wrote: post #20

Disclaimer: IANAL. This is a particularly interesting use of AGPL because it appears to contain a RESTful HTTP server built-in. To my knowledge, with the way AGPL works, there are some interesting wrinkles: - It is only intended to “trigger” when distribution occurs under some legal copyright law definition of “distribution.” - It allows commercial use of unmodified and modified instances of the licensed code, as lon…

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.

Re: Check If Email Exists

#48

Post by jlawer »

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…

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 customer and send you through a lower grade of outbound IP addresses.

Frequently new registrations are processed at once as batch imports from another system or from a partner. There is a need to remove these invalid email addresses pre-sending and hurting sending reputation.

Re: Check If Email Exists

#49

Post by throwawaysea »

This feels like a service that would be used by shoddy email marketers and spammers to reduce the number of bad emails they send, so that they can avoid being blocked. Their home page (https://reacher.email/) mentions lists uses like cleaning "large lists", which comes off to me as code for "send mail of dubious quality without tripping alarms".

Re: Check If Email Exists

#50

Post by madars »

Supermancho wrote: post #39
gh2k wrote: post #21

I hope nobody uses this for anything serious. I run my own domain and use - @ to have a unique email for everything I sign up to. I have no email address that this counts as anything other than "risky". If this opts me out of marketing mail then that's probably a good thing, but I hope nobody puts a password-reset or security/billing notifications behind it.

I use @ .

This looks fantastic --- can you share some tips of setting it up?
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