cleaning up an old e-mail list

[dvfr]

I have an e-mail list that I have been collecting for a few years now, and I know that many of the e-mails in the list are probably invalid.

I send out a newsletter to this list and I can see in the mail log that some of the mail servers respond that the user is not a know user or something.

I am trying to find the best way to write a script that will go through this list and clean out old accounts that are no longer valid. I have tried a couple of scripts that query the receiving mail server, but they don't seem to confirm that the email address is valid, only that a mail server exists.

Is there an easy way to do this? Do I need to look at parsing the maillog file in order to find these bad e-mail accounts?

Any help would be appreciated.

Thanks.

[Pig]

I think the only 2 ways you can be sure would be
1. parse the log as you suggested
2. send out an email asking them to click a link that updates field in the mailing list table. Then once you have given them enough time to respond, you can simply delete every row that has a null value for that special field.

Maybe someone else has a creative idea.