I'm looking for a list of now-defunct ISPs (i.e., compuserve?) and potential redirects to new ISPs.
If your intent is to try to update email addresses that have old email domains to new ones, take it from someone who did this with a few million records back in 2012: it doesn't really help much.
I had an old list of mostly consumer records that I attempted to update (old Southwestern Bell email addresses, Compuserve as you mentioned, regional variants of Ma Bell, discontinued AOL and Yahoo variants, older ISPs that were bought up by Comcast or Charter or what have you, etc.) Here's the thing: trying to fix these domains to see if the accounts were still active nearly always (I'm talking above 99%) no longer active. Generally, when someone has an email address that is discontinued, they've moved on to another provider.
It's just an exercise in frustration.
For what reason?
Did you try google?
Thanks you Courtney - that's good insight.
Retrieving data ...