how to know if an email is correct via MX records?

[doodlemunch]

hi i have seen a program that is being sold for 20 dollars that lets you input a list of your emails contacts and then it looks to see if they are valid email addressess or not i was wondering if it could be done easily in pb but sinse i have no smtp knowlage i came to ask

do i have to check with the mx records ???
how to resolve the dns and such ???

can anyone point me an exampel of how to interactt with a smtpp server??

thanks!!!

[PB]

> i have seen a program that is being sold for 20 dollars that lets you input a
> list of your emails contacts and then it looks to see if they are valid email
> addressess or not

LOL, what app is this? Don't buy it because it can't know. At best it would
probably send a test e-mail to see if the receiving server "bounced" it as
invalid, but we all know that MailWasher can send fake bounces and even
if a mail wasn't bounced, there is no way to know that the address is valid
and in use anymore (if the recipient doesn't reply to it, that is).

[doodlemunch]

it is possibel to know if the address exists by quering the mx server
of cource you can not know if the guy will answer or not but that would be stupit

i will buy it if i can not see a way of doing it in pb
but it is possible

For the specified internet addresses, mail servers (mx records) are extracted from DNS. Then Lost Emails tries to connect to their related SMTP servers, querying them if the above email addresses exist or not.

[dell_jockey]

checking the MX record only ascertains that the domain exists. It doesn't say anything about the individual mailboxes configured for this domain.
Check out http://www.dns.net/dnsrd/rfc/ to learn more about DNS.

[sock91]

it is possibel to know if the address exists by quering the mx server

So who collects it then?

[DoubleDutch]

You can check the mail records and find the path that it took first, unless the abuser has an email account on that server too then they must be pretty good at faking the info.

Take a look at fake paypal emails (everybody must have had one of them) - look at the source and compare it to a real paypal email.