From time to time a Blacklist will go permanently offline. Unlike a failed website that often goes down with little or no noise, a blacklist tends to end with a bang. This was the case with the recent loss of Burn-Tech. Blacklists typically have many anonymous subscribers using their lists, so there are only a few mechanisms that can be used to let subscribers know the end is near. Typically, the protocol is to Blacklist the entire Internet. This may sound extreme, but it is very successful at driving awareness.
For email admins the story is simple
If email admins get a positive blacklisting on their servers, they tend to go look at why the rejection rate for a particular blacklist has spiked. Once they do visit the blacklist website, they’ll get the complete story and can remove the blacklist from mail filter algorithms pretty easily. This typically happens within a day or so, but could be delayed over a weekend (as in the case of Burnt-Tech).
The difference is for legitimate emailers
Legitimate emailers subscribe to services like MxToolbox to know when they are at risk of mail rejection due to blacklisting. When we see an IP on a blacklist, we immediately alert you. When it happens for all our customers, we look into the blacklist and will suspend the blacklist and try to notify our customers of the change. While email admins may still block your email while they are removing the failing blacklist from their filters, this is only temporary. The good news: you didn’t do anything to get on the blacklist. It’s safe to ignore the blacklisting event, even though you may experience a few bounce-backs. Everyone else in the world is experiencing the same bounce-backs as you, but at least you know why!