Email Validation


New Email
Hi All,

I have a list of 5000 email addresses. I need to check whether these emails are existing. How could I do. I tried to send few test mails with gmail account. But I am not satisfied with the result. Is there any way to check?


IMAP Tools
Yes, you can do it the same way that an MTA determines whether a remote recipient is valid, through an SMTP dialog with his MTA.

I wrote a Perl script that can be used to validate a list of recipients. Here is how it works (using for valid and as invalid recipients).

1. Look up the recipient's domain in DNS to find the MX hosts which serve that domain.

2. Make a connection on port 25 to one of the MX hosts for the domain

3. Start an SMTP dialog with the key piece being RCPT TO:<recip> and reading the response from the server.

4. The MTA will respond by saying the recipient is OK or giving a reason why it won't accept a message for him. The recipient may be invalid, his mailbox may be full, etc. Any number of reasons.

5. Close the connection and write the results. For example: valid recipient address 550 5.1.1 <>: Recipient address rejected:

If you want a copy of the script send me an e-mail.



New Email
There are many validation services on the market. At NeverBounce, we do dynamic validation every single time we run a list. Many other companies do the same. Some however, run their lists against internal databases. Really depends on what you need.