In making a server change including a new IP address for our mail server, we inadvertently reactivated an autoresponder and also inadvertently sent out our stored double opt-in message to subscribers who tried to subscribe some time in the past, but who didn't actually click on the coded link to subscribe. I'm guessing that these are the mistakes that landed us on the SpamCop blacklist.
After learning of our IP address being listed, we immediately found the problem with the autoresponder (notifying our subscribers of no-longer-active email addresses) and turned it off. Unfortunately, after waiting the 48 hours, we're still on the list and worse, we're getting inundated with complaints from nonprofit organizations that they aren't receiving the list postings, eNewsletters, and help-desk responses they rely on.
I've personally spent hours and hours on this, trying to figure out what in the world is causing our new IP address to be listed. Apparently we're still doing something wrong but for the life of me, I can't figure out what it is. I'd be grateful to you for any help you can be. I did just post this to the on-line page for addressing this kind of thing, but am so desparate that I'm also posting here. Hope this is appropriate.