I have a question relating to email verification.
One of the things I do is run a couple of websites, I allow people to sign up for my newsletter and have several opt in forms (where people leave their details and get what ever I'm currently offering for free).
About 10% of the people who leave details are leaving *** data - this obviously means that when I send out a mailing my bounce rate is 10% +
This is acceptable for my service provider but it makes my stats meaningless.
I've just written a piece of code to go and 'ping' a domain:
System.Net.IPHostEntry objIPHE = System.Net.Dns.GetHostByName("www." + dnsName[counter2].ToString());
}
{
listBox2.Items.Add(dnsName[counter2]);
BaddnsName.Add(dnsName[counter2]);
}
which works fine and allows me to at least filter out bad domain names.
I've also added code that check the actual syntax of whats been entered.
This is again quite cool and has allowed me to filter out 5% of my data as just plain bad.
What I need to do next though is to find which mailboxes are valid (because I'm guessing that 5% is just the tip of the iceberg).
I'm aware that there is a simple way of doing this which is use the smtp's error/bounce log and then filter out the email addresses accordingly - but I'm using a service provider so I don't have access to the log files.
How can I verify the mailbox existence using a tcp connection (or some other way).
incidentally, if anyone is wondering why I'm trying to do things this way rather then the normal 'double opt in' process it's simple. The double opt in process typically involves you losing approx. 80% of your list - and I can't afford that drop right now.
thanks in advance,
Ed.
Email Verification
VBProEd
I was asking this question because I've seen countles articles and stuff about using the dns servers MX entry as a lookup table - and I don't know enough to understand how it works.
Ed.
mr Umesh kumar
(e.g. user1@mytestdomain.com)
by doing a dns lookup on the MX entry of mytestdomain, you are able to determine if a postoffice exist on the domain (e.g. exchange.mytestdomain.com). However, you will not be able to verify if user1 mailbox exist on the server itself. The only way you can do that is to send a email and monitor if it bounce or if any error message is returned.
Cheers!
roniay
If it was possible to verify an e-mail address then spammers would have a field day. What you want to do is impossible really. The only way is to send them an e-mail with a link that they click on, or monitor bounced e-mails and remove that addy from your database. And for your domain check, what if there is no "www." for the domain That doesn't mean the address is invalid.