When you request a delist, we process the delist immediately by removing the offending item from the relevant list(s).
Each list is rebuilt once per minute, so along with the reload times - it might take up to 3 minutes for a delist to be effective for people directly querying our service. We also have customers that copy our data and serve it locally themselves and in this case it might take longer for the delist to work (up to 15 minutes).
For all blacklists, except for Policy, we remove the listing entry immediately, but you will be immediately relisted should we see any further traffic exhibiting the same behaviour that caused the listing in the first place, so make sure you have actually done something to actually fix the problem before you request a delisting.
Policy Blacklist delists
Any delists on the Policy Blocklist are effectively permanent exceptions - you won't ever be relisted and the exception will remain until we notice that the rDNS has been updated for your IP address (at which point we will re-test it and remove it if it isn't required any more) and in the future we may ask you to reconfirm the exception once per year, so our data doesn't become too stale.