Verifying email adresses (ie with a ping)

[scottiex]

i wonder if anyone has had a go at using VBA to manage telnet to check if emails still exist?
or otherwise controlled it via excel for a similar task? (to get me started)

i know there are online tools but no-one wants to give people online their email lists so seems like such a thing would be pretty useful to a lot of people. Also people seem say it is conceptually straightforward.

link to apparently how it is done below

https://tools.emailhippo.com/Article..._Email_Address

[CheeseSandwich]

Hi Scottiex,

I don't think that you can ping an email address to see if it exists. I have just tested it on my work email and it does not exist, you may be able to ping to see if the domain exists - may not help you though. Below for reference - it is looking for a website or email, if it finds an email address it will replace the name part with 'www.' and ping it as if it was a website.

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Hope this helps

[6StringJazzer]

I don't think that you can ping an email address to see if it exists.

You can (subject to limitations as described at the OP's link) but "ping" is not the right term to use; the author is using a metaphor. ping is a telnet command to send test packets to a server and measure the response time, as demonstrated in CheeseSandwich's post. There is no ping command for email addresses. However, the link describes a method where you establish a telnet session to the email address's SMTP server.

The article at the link is several years old and many servers have taken a more defensive posture due to the proliferation of spam and phishing emails. Note that even in 2015 he warns

In some cases, will not be effective at conclusively determining is a mailbox exists or not.
....
The things that make mailbox pings technically challenging are the policies put in place by remote mail servers to prevent spam. In our example above, I purposely used a Gmail address because Google mail servers have a fairly relaxed policy on connecting to them and having a "chat". Most other mail servers will have policies in place that prevent connection from "untrusted" computers(yes, that means your computer).

The method depends on the willingness of the SMTP server to provide a meaningful response if you probe it with an email address. I have not taken the time to try to replicate the telnet session in his example but I know for certain that many SMTP servers will not tell you whether an email address exists because they don't want to expose that information to bots that are trying to guess email addresses. As mentioned in the article, it may not even allow you to connect. I will experiment with this and report, if time permits.

[6StringJazzer]

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Didn't get too far trying to replicate his example.

I tried the same thing using the SMTP server for my personal domain name and got the same result.

[scottiex]

Thanks,

I appreciate you looking into it.

I would be happy if it only works for say half the addresses. Although if it works for hardly any I guess making sure the domains exist is the best we can do.

Still, I presume the paid services must be providing a service that in theory (but maybe not in practise) could be replicated... unless we think it is all just a scam now?

[6StringJazzer]

What paid services do you mean?

[scottiex]

googling "email validation" gives me a lot of options.

earlier today I found one and it seemed to be working on the basic examples I gave it - but the ones I have found now seem patchy which would match with what you are saying about many servers have taken a more defensive posture.


edit:
woops I realized I just liked back to his site - I will try to find the one I was using earlier although I am starting to think its just the above situation...

[6StringJazzer]

Here's a service that does basically what your first link describes. (Not an endorsement, just a random example.) And it has all the same reliability problems that have been mentioned. Just for kicks (no pun intended) I signed up for a free trial. It failed to verify my email address on my own domain, and also a friend's on his domain. It did verify my gmail address, and a friend's AOL address.

I also tried the address of a customer service rep for a local company that I am a client of. I got this back:

This email address resides on an Accept All domain. These domains will confirm that every email address exists, even if they don’t. In these cases, we cannot guarantee an email will be delivered to a user's inbox.

I am not sure how it determined this was an "accept all" domain.

So I suppose the technique could work if you could program VBA to manage a telnet session (I've never done it). You can get false negatives and false positives.